This was originally a comment response to Nad Crushers worries It got a little long winded so I thought I'd make a post.
There is always going to be unbalance in this game. It may be a small unbalance, but it's there. After broodwars, Terran had the advantage. I'm afraid that Terran will have an advantage in this game too, maybe Protoss as well. But Zerg.. Zerg only had the upper hand in the original game, and it looks as if they won't have it here too.
The cycle of StarCraft ... Terran > Zerg > Protoss > Terran
Terran beats zerg, zerg beats protoss, protoss beats terran.
Of course player skill comes into play too! :D
Reactor?! As if Terran's marines weren't strong enough, especially with the medics, now they can double their production rate.
In the new video, did you see how many ultralisks attacks it took to kill an archon? And as great as that burrowing infecting unit is, it will be hard to pull off in a real game with turrets ,comsat stations, and now radar towers. It is nice to finally see a zerg unit that does splash damage, I have to say.
Protoss looks as if they'll be powerful as well. Their new ability to move units without the use of an arbiter looks promising. And, like usual they look very strong.
Now, I'm a Zerg player, and I've watched A LOT of Korean matches. I saw a huge upset with my favourite player, Lee Jae Dong. There was a match he obviously should have won but lost because of the class restriction. Even the announcers were confused as to why he lost a major battle using a large number of Guardians, Mutalisks, and Zerglings against a handful of Goliaths and Siege Tanks. For Zerg, the power always comes from number, not quality. Protoss, quality, not numbers. Terran is something in between. For Zerg, you always have to work really hard to win by getting a lot of expansions. Without this you are done.
I know this is just a beta and it's hard to get an idea of the game, these are just early thoughts. I'm really excited to see this game. And I'm really excited to see it being played competitively. I just don't know if I'll be playing Zerg anymore.