Don't get me wrong man, I love the 2600k, LOVE. But unless you are folding, encoding, 3d Video editing, etc. you won't really see a difference.
Anyway. since everybody seems to be suggesting different cases and a bigger motherboard, I looked into it, and found this motherboard to have pretty much everything I'd want:
(I'd have to buy a wireless card, and I think I'd add a sound card to fill the last slot)
But that leaves the problem of the case. I've narrowed it down to these:
-Lian Li PC-A04 (seems nice in just about every regard...but I hate the "chrome" interior)
-Silverstone FT03 (like the design, and how you have to have a slot-load drive...but looks like cable management might be a pain)
-Fractal Design Mini (I'd love the sound-dampening features, but I'm not sure how negatively it'd affect cooling, and I don't know of a place that sells it)
Of course, if somebody can recommend a really compact ATX case that will still fit the GTX590, I can look into it, but I can't promise I'll like it