So you think 3470 is good enough. I would like to run games life Farcry 3 or crysis 3. No change for next 3 years..
If anything, newer games will be stressing the GPU far more than your CPU. The Core i5 3470 is a very capable CPU to begin with and is likely to have 2 of the 4 cores idling, most of the time with a few exceptions, while gaming.
Games are, however, becoming more and more multicore aware. That means that you've got 2 cores to spare for future titles.
Your GPU ought to be the main point of focus for gaming.