I agree with a lot of the guys in here. You should upgrade your CPU when steamroller launches, it could take a while, but it would prove to give you more performance for your money. When it launches you have probably also saved enough money for a new GPU, so you could upgrade both. Either upgrading CPU now or GPU wouldn't prove to give you a huge noticeable increase of framerates in games. Only if you were to upgrade both.
You could maybe do a slight upgrade on the CPU if you're eager to upgrade right away. FX 6300 is priced around 130$ and you might get lucky and sell your current CPU for 60-70$, by doing so you could get a cheap upgrade, that would let you squeeze some more GPU power out of the system. So you could move a little up the GPU hierarchy.