yeah your core 2 duo will hold up fine for now but certain games that are optimized for quad cores (BF3, Crysis 2) then you will find yourself scaling back settings a good deal to get them to run smoothly... however the cpu you have is fine for now and it is certainly well matched with the gts 450 or gtx 460 768mb... both of these cards will not cost you an arm and a leg and you can save your money for a better build. But, by no means do you need an i7 to game, its basically a waste unless you are running triple monitors and sli, etc. An i5 is more then good for a future purchase and the AMD bulldozer cpus and mobos will be out in a few months. For now the best thing to do is get the psu and gts 450, game on that for now and start saving, the gts 450 will at least give you a good taste of what a modern gpu can do potentially. As far as crysis 2 goes you will be able to play it, but not at 1080p and all high settings. The game is only is dx9 and as so it will run a little better than the original crysis which brought any system of its time to its knees...