Will this build work? and is it good enough to play new games at high or max settings? I'm building this computer to play sc2 and modern warfare2 and other new games..
I might upgrade cpu to i5-760 but I don't know if the difference is noticeable..
OCZ power supplies are decent quality, I say keep it, just stay away from their RAM.
600 is enough for what you want, but you should get a 700 for future upgrades.
And definitely change to the HDD Pizza pointed out. It's the newer version. It's faster and more reliable.