My biggest man-squee is for the four-player co-op. Marcus, Dom, Cole, Baird, I'd assume, although it'd be awesome if you could choose different ones.
Dom's got a serious case of Grief Beard going on there.
Max Payne's inclusion in that list hasn't really been justified, is it.
Also, Jim Raynor should be on that list.

So, anyone wanna take the time to explain GoW canon to me? I've played the first two, but I do not understand the story at all.
Humans fuck themselves over an allegory of oil, war ends and then aliens come up afterwards to fuck them too.
Right now that's pretty much all there is to remember when you're playing the game. Also Dom euthanises his wife which is the cause of Grief Beard, but like Yahtzee once said no-one cares about the cunt wife except for Dom and they're all kinda just like "there there".
Thinking over the first half of the announcement trailer Dom comes off as ridiculously emo, like Aerith-died emo. I mean I know the Gears franchise isn't exactly the most subtle thing ever but when you're being bludgeoned over the head with metaphors remininding what happened "PREVIOUSLY ON GEARS OF WAR 2 AND THE WHIZZ BANG ZOWEE TUNNEL CREATURE WAR" it does get a little grating, I suppose.