Phenom can still push a Nvidia 660 without problem. The Phenom Architecture has 4 cores and the Single Threaded performance of the Phenom is still good enough. So, I believe it was the right choice for $100.
This build should last for 2 years without much problem. This rig can play games at 1080p high 30+ FPS.
If a build can play games at 1080p at good settings, then it is considered to be a good rig which your's is. Hence this would serve you fine for the next 2 years.
Just upgrade the RAM to 8GB, other than that everything is fine with this build.
If you have any other question, then feel free to ask.