DaMeiNTheir's 1 Sniper, 2 or 3 engineer classes, 1 huntsman Sniper?, 1 soldier, 1 scoutish class, 2 melee heavies, 1 medic, and a gun spy...
Before even reading this thread, this is about what I said to myself when watching the trailer, only difference being the dude with the hammer is just a big demoknight with the medics MvM shield.
I wonder if Blizzard is purposely aiming for the TF2 audience. The casual TF2 scene is still really big, and would be a good jumping off point for the game. I'm sure Blizzard would love to get back at Valve for the whole Dota 2 fiasco, if only a little.
EDIT: Just noticed why a lot of you guys will obviously love this game. No pyro.