It really just depends. Bottlenecks occur in every demanding program, it's figuring out which component is holding you back first (RAM, CPU, GPU, etc).
If you're talking about gaming, @ 3.2 GHz I don't think it'll be all that much of a bottleneck. Since you have a decent CPU I wouldn't worry too much about it. That said, you would probably gain some frames if you got a i7-2600k.
Gaming is far more dependent on the graphics card than anything else, so I would say upgrade away.