4670k is pretty much the best chip you can have for gaming unless you like pissing money into the wind. Consider these benchmarks. You can run a $1000 4960x IB-E chip for a negligible improvement, but that's about it. The reason you don't bother with 4670 still is because it's $150 more for little to no improvement unless you're already dropping $400+ on a video card. If you are in the market for a 290, then by all means, go with Haswell.
//EDIT: That's not to say that either the 4670k or 4960x are improvements over their predecessors, because they really aren't.