Well, first off, your motherboard will support the newest AM3+ Cpu's. So, while the i5 isn't a bad upgrade, you could spend a lot less money and still get a better performing cpu. The 4690k vs. the fx8350 will gain you about 15FPS using the 770 @ 1080p though. 45FPS vs. 60FPS'ish or so. http://www.hardwarepal.com/2014/01/28/planetside-2-cpu-benchmark/
So, you'll have to decide if it's worth the extra 200 dollars or so for an i5 setup and 15FPS.