We've got a couple of decades of Sony history to draw from, and plenty of unique characters to borrow, so let's go nuts.
Cole MacGrath: From inFamous. Duh.
Ratchet and Clank: Obvious. But they would be great, wouldn't they?
Nathan Hale: I'm sure he'll be revealed at E3. Let's move on.
Solid Snake: !
SackBoy: Get the hell out of here if you don't think there won't be a SackBoy fighter.
Crash Bandicoot: This swirling, spinning, crazy-eyed derphole would be a riot to play.
Jak and Daxter: While we're on Naughty Dog, how about using their classic hero duo. I'd love to see them as a single unit, with Daxter being whipped out for special moves.
Piposaru: The silly monkey from the Ape Escape would be hilarious as a fighter.
Nathan Drake: C'mon. Him and Sully. I'd put good money on both being in. Drake could throw Subway sandwiches as projectiles.
Kat: Gravity Rush's main character is already a favorite of mine, even if the game has not been released here yet.
Ico: Sony, don't mess with me. Ico better be in this shit, and he better have Yorda out for special moves. Some would think of this as pooping on a Sony classic, but I want it, so don't listen to them.
Wander/Wanda: I would never ever play as any other character if Shadow of the Colossus' main man were included. Well, except for maybe …
P.J. Berry: Parappa's fat, lazy, mumbly DJ bear sidekick is still the greatest character ever to come out of Sony. I don't even want this game if he's not in there. While you're at it, also add UnJammer Lammy.
Sony has so many properties to pull from for stages that I'm guessing that the development team behind All-Stars had a blast putting them together. I can't wait to see what they do with the varied properties. For now, here are some good guesses for what to expect.
Motorstorm: There's nothing to use for characters, but some of the crazy stages of this racer would make for nice stages.
WipeOut: They would be wrong not to make a WipeOut stage. It would be compared to Nintendo's F-Zero stage, but I think Sony could do a better job with theirs.
Gran Turismo: This is yet another racer that could make a decent stage. If not, they can use that silly helmeted racer from the opening cutscenes as a playable character.
Team Ico's worlds: Both Ico and Shadow of the Colossus would make beautiful stages. Or, mash them up into one.
Warhawk: Could be fun. Probably not.
thatgamecompany: Journey would make a nice stage, and working in elements from flOw and Flower could make for a pretty stage.
Sony has the pull and plenty of partners, so why couldn't they do this? It's not a stretch in my mind. They could phone in the following to include them in the game's roster, or at least add them as DLC. By the way, I predict that the amount of DLC for this game is going to be bonkers.
Pyramid Head: The poor bastard has been run into the ground by Konami, so why not go all the way and stick him in this Sony brawler? Sword fighting from the Silent Hill creature is a given, but maybe his level three super has him doing the nasty with his mannequin legs girlfriend, causing onlookers to pass out and KO in disgust.
Travis Touchdown: Eh, I don't know. The No More Heroes sword whacker might not fit. Still, how great would that be?
Kazuma Kiryu: Yakuza's main character already has all of the fighting moves built in. Easy choice.
Isaac Clark: The Dead Space protagonist doesn't have much of a personality, but he is enough of a badass to make it work. His weapons would make for a fun character.
Big Daddy: BioShock's big, grumbling asshole would be the meanest fighting game character of all time.
Sony is all about the Vita these days, and we know the system can do cross-platform fighting beautifully (see Ultimate Marvel vs. Capcom 3 or the upcoming Street Fighter vs. Tekken for proof), so why not a Vita version that can support match-ups with other PS3 and/or Vita players?
What did I miss? What would you like (or hate) to see in PlayStation All-Stars Battle Royale?