On paper, the D7000 looks like a good option for wildlife, and I'm considering it for exactly that. With small birds one can never have enough reach. When the bird is too far away even for my longest lenses, I often end up cropping the final image to about the DX format anyway, which is just 5MP when starting with a 12MP FX image. The D7000 would give me 3 times that! That might outweigh any FX image quality advantage.
My only concerns are how fast will the AF be - will it be closer to the pro bodies or the consumer bodies. I'm not concerned with the number of AF points, just the acquisition and tracking speed. If Nikon has plans for a DX D400, it may have reserved the fast AF for that body. And the other concern is will the body be too small and flimsy on a super tele lens to handle well.