I bet there will be a lot of Sad Sally's for people who are choosing light builds...I keep seeing posts like "I wanna be quick and stealthy, killin with my knife and sniper." ...well, you guys are in for a rude awakening.
Also, being light doesn't make you any sneakier or stealthier - that's what Operative are for...which ANY body type can be. The only advantages you get for being Light is speed and mobility - that's pretty much it...you don't get access to exclusive weapons, (Heavies do) you don't get a sniper or knife damage modifier, you don't get a backstab ability (again, this is Operative)
Still, they haven't released any of the game types and they have definitely been working on stuff. In general, there is not a lot they can do with gametypes, imo the major variation will come in body type specific game types, so light can only face light; med, med; heavy, heavy.
Even if people do find out light svcks in comparison to the other two, fans can switch to PC and utilize dedicated servers.
I like the non-one hit knife, but the X>1 bullets to kill with a sniper sounds annoying. Not because I am a fan of snipers, but because that implies that if they weren't they might become overpowered, which implies the corridors will be longer than we expected... they better add a lot of cover to this game, and hopefully flanking routes.
edit: reading the forum, I really don't wonder at why heavies rage at lights, and lights rage at heavies anymore. Seriously, if a heavy can easily take out lights that would be utter BS. How it roles with light vs heavy is lights lag a bit and heavies are an easy target. Light needs a lot of easy hits, heavy needs a lot of lucky hits. Needless to say both take skill, its just that I hope SD allows players to avoid as many unfair adv encounters as possible, by separating body types into game modes for consoles. I always hated juggernaut in CoD4, and I hate slow-paced game types as well. Screw realism, hardcoe is boring for me, the faster the game the better.