990x and 590 SLI

To be honest - wait. In fact, with 590s you don't even need to upgrade at all, but I guess you're an enthusiast.

wait until Ivy Bridge Extreme, get the absolute top of the range CPU, and then get two GTX790s or whatever they will be. Ivy and second gen Kepler should be good. I'm starting to get really anti-AMD, and look at my computer... Can't accuse me of being biased. But to be honest I'm wondering if it'd be worth getting my mates pair of 590s and put them in my 990x system as well... I just got the AMD because my brother was going to buy my 990fx and it was a little excessive for my needs at the time. He never ended up buying it, but I'll almost definitely be going for a top of the end i7 and 790 SLI system when they come out.

Only reason for saying don't go for AMD is that the processors are to be completely honest, crap, and the GPUs are problematic at best. This was my second AMD build and unless they pick up their game, will be my last.

Are you overclocked? I'd wait for Haswell IMO.

Can you honestly say you're unhappy with any of your performance? =P

What is your resolution? The higher, the less the CPU has to work.

An overclocked 990x is still an extremely impressive CPU these days.

I will admit an IB-E could be beneficial, however I'd wait it out for Haswell and another step in the GPU world. Games haven't really been pushing it these days.

Wait until skylake.