This years have better integrated graphics, if you ever might need that some point(nice if your video card dies and you have to run on integrated graphics while waiting on a replacement), but other than that, if you can save a few bucks, I probably would. I still have the 3rd gen i5, and i5 3570k, and it's great for gaming, and overclocks super easy as well if you are in to that.
Basically, each gen of I5/i7 processor has gotten progressively more energy efficient, better integrated Intel HD graphics, but harder to overclock. Pure bottom-line performance has basically not changed as far as gaming is concerned. An i5 2500k(2 generations ago) is almost the exact same performance-wise in gaming as a current gen i5 4670k