Left 4 Dead 2? Seriously?

During the Microsoft E3 press conference, Left 4 Dead 2 was announced. Let me get things straight here, I'm a big fan of Left 4 Dead, in fact I paid cash-money for both the PC and 360 versions, and I've been eagerly anticipating more L4D. Still, I can't help but feel a bit offended that Left 4 Dead 2 is coming out this soon.

When Left 4 Dead was released, it wasn't a complete product. Of the four campaigns included in the game, only two were usable in the versus gameplay mode, the meat and potatoes of a long-lasting Left 4 Dead experience. Since then Valve has remedied that situation with a free content pack, and kudos to them for not taking the low road and charging for what should have been in the game in the first place. The official excuse from Valve as to why the maps were left out at launch was that the versus levels take too long to set up and test. Nevertheless, we are being given a new and hopefully complete game in less than a year? I'm going to have to call shenanigans. Merely seven months ago I was charged a full $60 for an incomplete game, I'm not falling for it again.