New Super Mario Bros. Wii is on the fast track to becoming one of the best-selling games of all time. Less than three months after release, the game has already moved more than nine million copies worldwide, and shows little sign of slowing down.
Among other things, that means that the game's two new characters, "Blue Toad" and "Yellow Toad," are quickly becoming two of the series' most well-known characters. But these two still don't have any officially sanctioned names. All we have are the nicknames that the guys who made the game used for the characters. Why would Nintendo do such a thing?
The developers are known for behavior that doesn't make any rational sense, but there is usually a method to their madness. Here are a few theories as to why Bucken-Berry and Ala-Gold have become two of gaming's most well-known, anonymous weirdos.

Princess Peach hates peasants
Okay, maybe that's a little strong, but there is definitely something up with the fact that Toad and Toadette (the characters) have the exact same name as Toad (the race). It's like naming the two black characters in a movie "Mr. Black and his wife Choco," or how King Arthur in Monty Python and the Holy Grail calls that 37-year-old man "Old Woman." It's quite like royalty to treat their subjects as if they're all interchangeable: faceless workers whose only identity is "not royalty." I mean, even the Donkey Kong gang, a bunch of talking apes, have their own names. Toad, Toadette, and almost all the other Toads don't even get that. They are less than monkeys.
King Koopa is no better. Other than a few exceptions like Kamek and the Koopalings, his "people" are known by their race and their color only: Red Koopa, Green Koopa Paratroopa, etc. I guess it's only fair that Yellow Toad and Blue Toad share the same nameless fate.
Nintendo didn't think we could handle names
Nintendo is famous for making games that are easy to pick up and play. One of the ways they succeed at that is by limiting the amount of information the player is asked to take in before they start playing. For instance, when Mario first showed up in Donkey Kong, he wasn't called Mario. He was just called "Jumpman." That was all you needed to know about him: he jumps, and he's a man. New Super Mario Bros. Wii has a similarly minimal approach to storytelling. No names, no introductions; just a kidnapped woman and a rescue party.
For a game made for gamers and non-gamers alike, it makes sense. I don't know how many times I've introduced a game to a non-gamer, only to have them lose interest because there is "too much talking." I'm not talking Metal Gear Solid of Final Fantasy VIII, I mean games like Zack & Wiki and Ghostbusters. Non-gamers don't want information. They want to play right away. They don't want to have to think.
Telling us who these new Toads are would take up valuable seconds, and might cause some of us to think. That could potentially detract from the player's ability to slip into the experience of New Super Mario Bros. Wii, or at least, maybe that's what Nintendo's thinking. The fact that I'm writing this post shows that leaving the new Toads unnamed has made at least two people on the planet (me and you) think a whole lot. If that was Nintendo's aim, then I guess they failed.

Nameless characters are easier to relate to
Maybe it's not that Nintendo thought that naming the Toads would make the game worse. Maybe they thought that leaving them unnamed would be better. Playing as a completely anonymous character is a rare event in gaming today, though it used to be commonplace. I still don't know the name of the disembodied eyeballs that star in the Atari 2600 game Haunted House, or the name of the guy in Berzerk, and yet I'm still talking about them. Would I still remember then if they were named something stupid like "Mr. Pupils" and "Magnus Robot Fighter"?
Yeah, probably, but I definitely wouldn't remember them as fondly. Leaving those characters nameless probably made me like them more. Just as the silent protagonist allows players to speak for them, a nameless protagonist can be anybody. I've already met quite a few women who are convinced that "Yellow Toad" is a woman too, and that's why it's the only character they're willing to play as. That might not have happened if Nintendo had given he/she/it a name.
They don't care
Out of all the theories here, this is the stupidest one, but also the most likely. The minds at the highest level of Nintendo are extremely focused on the fundamentals of game design and creating accessible experiences. They aren't focused on crafting a world populated with deep and complicated characters. Nintendo has made it clear that there is no firm timeline for the Zelda games, despite the fact that fans desperately want one. Miyamoto has also said that story isn't important in Mario games. It's not too much of a leap to think that they just didn't think that we'd care that the two co-stars of one of their biggest games ever don't have names, because they didn't care.
Then again, they do have names, they just aren't official. That leads me to my last idea...

"Bucken-Berry" and "Ala-Gold" mean something bad in Japanese
I've heard some theories about this, but not being a native speaker of Japanese, I can't be sure. Phonetically, Bucken-Berry is "Ba-Kun-Beh-Lee" and Ala-Gold is "Ah-Ra-Goh-Du." "Baka" means "jerk" and "Kun" is a suffix that means "little guy," sort of like using "Y" at the end of "Johnny." So, maybe "Ba-Kun" means "jerky"? That wouldn't be such a good thing by Nintendo standards. I'm not even going to venture into what the other names might mean, as I have the feeling that I'm butchering this translation process as it is.
I guess I'm just hoping that Nintendo has a good reason for not running with the Bucken-Berry and Ala-Gold thing. More so, I'm hoping the names are formally used in future games. The names have really grown on me, and there is just something off-putting about the fact that Nintendo hasn't embraced them.
These two little bastards have warmed the hearts of whole new generation of Mario fans. The least Nintendo can do is give them names.
[UPDATE: I just caught wind of this 2010 New Year's card that Miyamoto drew. I can't read the Japanese here, but it is notable that the card features Mario, Luigi, Bucken-Berry, and "regular" Toad. Did Miyamoto mix up "regular" Toad with Ala-Gold, further promoting the idea that he just doesn't care about these new characters, or is there something else going on here? MYSTERIOUS!]

^--- Tag of the century.
THEY'RE NAMED FREAKIN BUCKEN-BERRY AND ALA-GOLD! XD
Pretty fun article to read; I enjoyed it.
Toads aren't special. They're just average citizens of the mushroom kingdom. They don't require to be given proper names.
I need to make my wife read this article; she ONLY plays as Yellow Toad and HATES the dialog in videogames (a fact I just found out yesterday as I played through Uncharted, of all games).
Same with the Yoshis, The character's name is Yoshi, but that is also the name of the race. You can call every Yoshi "Yoshi" as it's name, and it still means the race at the same time. Also the same with Magikoopas/Kamek. People always get confused as to whether or not the Magikoopa currently on screen is the one and only Kamek, or if it is a different individual of that same race. It's because in Japan it's one and the same. Every Magikoopa is Kamek.
This is a really odd concept to grasp at first, hopefully I've done a decent job of explaining it. :/
I think Iceblueslushy has the right idea. Plus, every Toad with a name has a creative handle like, say, Toadette. Might run out of options if they blow that load too early.
Good article, Holmes!
King Koopa and her have a thing going. She gets freaky and he gets children.She's "kidnapped" so he can plant and sow his seed in her and then she's given back to Mario, who's too busy collecting coins and stoned out of his mind dressed up in a Bee Suit to really know what's going on.
Also, I accept cash or paypal.
<3
For the record, a 2-D Mario game with co-op is not an original idea either; it's just something they haven't done yet because Nintendo is too busy with rehashes that they have to keep a small list of ideas that could make Mario seem not-as-exactly-the-same as the games before it, or else the fanboys would get finally start to think "Hmm, haven't I been playing this for the past 20 years?", so every once in a while Nintendo has to add SOMETHING to keep the series a little compelling once in a while.
And yes, I realize this a troll-like comment. Get used to it.
Congratulations! You out-Samit'ed Samit!
Do they really need names? Not necessarily, but it would have been nice. Would have given them more of an identity, but maybe that's what Nintendo wanted to avoid?! I agree with Poe and others, the fourth Mushroom Retainer should have been Toadette. Or at the very least Nintendo could have given players a palette of colors to choose from. Imagine a black, purple, orange, red or pink Mushroom Retainer? How sweet would that have been?
By the way, I beat the game solo a few weeks back(100%) and just last night beat it again(not 100%) with a friend and the game still manages to bring a huge smile to my face! <3
Also, that Miyamoto New Year's Card drawing made my day! =D
Because, seriously - even though I consider Waluigi a pointless character, I would choose him hands down every time over a generic toad. As for Wario - anyone who doesn't like Wario is a communist. There, I said it.
Well I was going to say something regarding your comment on the plot of the story, we all already know it doesn't need one at all, it's short sweet to the point. Rescue the Princess that should have been in the Kitchen making more food.
(Room goes "OOOOOOOOOOOOOOOOh!"
I kid, I kid.
Seriously though, I think that if they put those two in instead, it would have made it a little more difficult to differentiate them all, maybe. But then again, why would Wario and Waluigi even wanna help them out? Unless they'd get Money...
I think the normal Toad is the one that you have to escort through a level from time to time. They're just playing a three-player game is all.
"But then again, why would Wario and Waluigi even wanna help them out? Unless they'd get Money..."
Yeah, that's what I mean as far as "Put something in the plot that makes them join Mario and Luigi". I mean, hell - if they could get Bowser to join up with Mario in SMRPG, I'm sure they could figure out something for those two.
Maybe Bowser kidnaps Mona as well?
@ Holmes
You made an error (as you suspected) in your Japanese analysis. The -kun suffix is mainly used by boys to refer to fellow male friends in a familiar way, as opposed to an unfamiliar way (no suffix) or a more respectful way (the -san suffix). (Girls can also use it, mainly to refer to boys.) It is also used in a diminutive sense to refer to younger boys even if you aren't familiar with them, but this is also a subset of the main usage. I can see how you might have mistaken this part of the usage for "little guy," but it's incorrect.
Furthermore, breaking down the names into their Japanese pronunciation would be (rendered in romanji) Bakenberii and Aragourudo ("ou" being a longer "o" sound). Unfortunately, my Japanese vocabulary is fairly weak, so I don't see any Japanese wordplay that those names could mean.
Also, when I play with 3 friends nobody wants to be stuck with Luigi and chooses their character as quick as possible. Was it like that for some of guys too? Luigiphobia is a new illness. It must be his sexy dance in Brawl.
Co-operative versus mode of Out of Shape Plumbers v. The Wonder Twins is, by far, the best way to play NSMBW.
So, they've been messing names up for almost 30 years now.