djangoringo :
You'll be disappointed by it's performance, with the apu it will be barely playable(you'll get framerates even bellow 30fps on low on recent games and i mean at 720p) and for me the apu is not a good solution, either go with a i3-i5 +h77/z77 mobo+7750/7770 or hold and save some money for a better system, the cpu that you have ain't bad it wont bottleneck a 7850 and with that you'll get the framerate that you'll need.
I've seen people with your type of cpu on online games with recent cards and no complains.
Seriously the apu solution is more for htpc than gaming, for gaming it's still not a viable option.
I can bet that you'll have even lower performance in gaming compared with your older parts.
In most modern games, the A10-5800K should not have any trouble in 720p with low settings. For the money, the APU is great. It's a nearly as fast as an i3 gaming CPU paired with approximately a Radeon 6670 DDR3's worth of graphics performance all for the price of an i3. If you want to talk about its graphics being too weak, then I suggest you get some perspective on it and learn how fast it actually is. Also, please realize that the A10-5800K with a Radeon 7750 or 7770 would be approximately as fast as the i3 with it, but much cheaper. I do agree that since OP's CPU is still adequate, it would not be ideal unless OP wanted to change platforms now and upgrade all components later for cheap, but don't exaggerate the situation.
Furthermore, depending on the gaming situation, the Q6600 can still bottle-neck a Radeon 6670 just like a Radeon 7850 and such can bottle-neck say i5-2500Ks with big overclocks in some situations. There are no absolutes when it comes to what CPUs can bottle-neck what graphics cards because it depends on the game, the games settings, and much more.
Also, the Core 2 Quad Q6600, at stock, has inferior performance CPU to the A10-5800K, so the somewhat weaker graphics might actually be offset in many situations by the faster CPU.
Regardless, OP unless you want to change platforms right now, I recommend that you stick with your current CPU. It's still decent and should be able to do the job. A graphics upgrade to say a Radeon 7750 would be a significant improvement over your 8800 GT while using less power (something that is not to be ignored on old power supplies because they wear out over time, so lessening the load can be beneficial to their continued longevity) and wouldn't be very expensive.