The screenshots of it looks nice , I am not sure I want to buy it yet. Will download the demo and try it. Have to check the screenshots again for Bioshock must have missed something.
I mostly play Wolfenstein ET / Fear / Graw / C&C all version / mahjong to keep my brain from slowing down. LOL. Graw 2 = american army free game in disguise = not impressed with it , rather use bugs galore graw 1.
Your q6600 and a *800 ati or nvidia card should run extremely well be it 6800 , 7800 , 8800. The us$309.00 xfx 8800gts should last you at least 2+ years games wise minm. and will likely outperform the current game standards = limited by new laptops / apple laptops + games = ati 2600 or nvidia 8600m.
I love this 7800gtx laptop video card I have it might be a 3 year old model but still rocks like mad with graw at 1440x900 and everything maxed = 75C to 90C temp occasionally but keeps it nice and avg at 60fps , even more if I use external monitor and switch the lcd laptop screen off , can also use med powermizer setting for 65C avg temp.
Supposedly graw 2 works on less serious hardware + it is cleaner code and lots of bug fixes but I do not like it as I am not a military man.
Comparison chart: http://www23.tomshardware.com/graphics.html
The real performance can only be seen at max resolution for Oblivion , outside scene on this linked page but you can play it in cedega / wine weard.