Most of the games you mention are fairly low powered and were around at the time of E8400 and GTX280 or even earlier.
Your GPU will be a fair bit quicker than a GTX280 in most games (it's a few generations later, the equivalent AMD at the time was probably a 4870). The GPU won't be the problem in your build - don't worry about it.
Your CPU will be a bit quicker in most games than an E8400, although not by as much.
The point being that the E8400+GTX280 combination got reasonable frame rates (mostly 60+) in games from that era. Here's a comparison of an i3 2100 and 280 vs E8400 and 280 on some similar games. The 2100 is slightly slower than your CPU.
http://www.anandtech.com/bench/Product/56?vs=289
As you can see, Crysis Warhead, Fallout 3, Far Cry 2 are all reasonably good (40fps+) on a slightly lower resolution than your 1080p - you can expect AT LEAST this performance. If those frame rates were GPU bound, you'll get better than those shown. If they were CPU bound, you'll get about the same.
So there's really three answers here
1) Will you get decent frame rates?
Yes, in most games. CPU bound new games might start slowing down, but anything more than a year or so old, or which are moderately taxing on the CPU should be fine
2) Will your CPU hold you back?
Probably not, but if you do play any games which start slowing down, your CPU is likely going to be the first component to start causing a problem - it will bottleneck the graphics card, if you hit the point where you're maxing the CPU... which is, as I said, unlikely with the games you're mentioning.
3) Will your GPU hold you back?
No. It won't handle the best newest games on max, but your CPU will cause problems long before your GPU does.
My advice is to just start playing the games you want to play, the ones you're mentioning should work fine. If you get into a newer/more taxing game (Crysis 2, Rome 2 Total War etc) and start hitting a problem, keep an eye on CPU+GPU usage to see which is the problem. Chances are it'll be the CPU causing the problem, and you can just sell it and drop in a faster i3 or an i5. Most games are biased towards the GPU anyway, so you'll probably get away with your CPU for a while longer.
