That system should be able to run most games. But that motherboard and cpu seems to be outdated since new Intel and AMD is coming out soon. But then again that system should be able run any current games out.
Your Case and PSU choice is fine... but if you like I can suggest an alternate way to go. Most Rosewill PSUs should be avoided but this is at least equal in quality to the OCZ, and will cover a single card well, along with the rest of the system. This particular PSU is made by ATNG:
Even though there's always room for improvements on any system, the parts you chose will work well together. If that's your 2011 "dream machine" go ahead and build it. It's fine....... before I go to work I gotta add........... the power supply won't be good for a cross fire set up. Just wanted you to know that.