oh and i just noticed i put 2.6ghz but it's actually an OC's e8400 to 3.6ghz. so, yeah not slow. and b4 u say "quad core is much better" it isn't. almost no games or other programs will ever use your 3rd or 4th cores anyway
Take another look at the pc games that came out this year and then say that again. Even black ops uses 4 cores

You don't require a dual core in most games, but you'll definitely by cpu limited with a decent card. Plus 2010 is probably the last year of the dual core.
Anyways, it's not like quads are expensive, an athon II X4 630 is £63 and will teabag an e8400 into oblivion ^^
Regardless, the game won't use steamworks, but will be on steam. You will also be able to buy it in a shop! I'll probably buy a hard copy, just because the case will be cool to have, depending on whether or not im willing to risk not playing it on day 1 (steam is very reliable for being able to play, pre-load it and fun times).
Also, lol, at 'zomg no mod tools, servers ect.', that guy has never used steam obviously. I have a billion server tools in my 'tools' subfolder, and quite a few SDK's.