I hear the D600 is calling my name as well, but I'm resisting. Moving from the D7000 to the D600 will give me more capability, not skill. Poor exposure or composition on the D600 won't look much better than on the D7000. I'll just wind up with larger file sizes.
Consider upgrading your lenses first. I'll go to a D600 or other FX body at some point, but am investing in good FX glass first. That way the transition won't be so financially brutal.
Received my 24-70mm f2.8 yesterday and put it on the D7000. The test shots were amazing. Had a similar experience with the 70-200mm f2.8 a few months ago. Lenses can generally give you an easier step up in the IQ of your photographs than a more expensive camera.
Nikon considers the D600 as an entry-level FX camera for consumers. You can buy them legally, even if you're not a pro! (just kidding)
If you're at a point where you feel your skills can take advantage of the additional capabilities of a FX camera, go for it.
"Red is gray and yellow white, but we decide which is right ....and which is an illusion"