Hi, not sure I'd upgrade to an AMD FX 4100 system. "FX-4100 And Core i3-2100 Go Head-To-Head" http://www.tomshardware.com/reviews/fx-4100-core-i3-2100-gaming-benchmark,3136.html
check hierarchy table here for fx-4100 http://www.tomshardware.com/reviews/gaming-cpu-review-overclock,3106-5.html
fx-4100 is only 2 tiers up from where you are now. Three tiers is recommended min upgrade in article.
Suggest you check performance with the new video card you ordered. You might find you have at least a little beast. IF the frame rate is good consider keeping cpu for another 6 months/year and a good gaming mouse, new monitor, good headset, etc. for the $250. Or play with an SSD drive (180-200GB for $250?). Or kick in a little more cash and get an i5-2400, MB and 4GB ddr3 memory. In 6 months or so we should see if AMD can fix up BD to be at least a mid-tier CPU. Today biggest AMD loses bigtime to intel in gaming. (not cause AMD is bad, but because intel sandy bridge processors are animals. )