No harm at all. As long as you can afford it. You can also OC it into a 965. Or get a Rana & see if you can unlock it's cores.
It's just that, for gaming, GPU power is more important than CPU power. But more CPU power certainly has hurt no one
But if you do have the extra budget, depending on what games you're gonna play & at what resolution, you might also wanna invest in a more powerful GPU - GeForce GTX 460 (Fermi) < Not needed if you wanna play WOW/SCII @ 1440 X 900 or something.