The D7000, while good, can't compete with the low noise floor of an FX sensor. Although I own a D7000, in my situation, the money would have been better spent on a used or refurbished D700 instead. Coming first from a D70, then a D90, I swore I'd never buy another DX body, mainly due to the smaller sensor's higher amounts of chroma noise. But at the time, I was interested in shooting video, and the D7000 was the first and only Nikon DSLR available to offer video acquisition using a modern AVCHD-based CODEC.
I do enjoy carrying a smaller body for times when photography isn't my primary goal, and as a result, I now own three DX-only zooms to support my "D7000 system." Here's a summary of my recent DX investments:
Nikon D7000 $1,200
Tokina 11-16mm f/2.8 DX: $600
AF-S Nikkor 17-55mm f/2.8 VR DX: $900 (refurbished)
Tokina 50-135mm f/2.8 DX: $500 (used)
Again, that money would have been better spent on a D700 body, and all-FX glass. I realized my "mistake" a few months after I bought my Tokina 11-16mm f/2.8. For the same cumulative investment I made in a new DX body, and a DX ultra-wide ($1,200 + $600), I would've already been in used-D700 body territory (especially, since I already owned an FX ultra-wide). Instead of the above "DX system," I could've purchased:
Nikon D700 body: $2,200 (refurbished pricing at the time)
AF-S Nikkor 24-120mm f/4.0 VR: $1,099 (refurbished)
Also, the D700 is just the right size--not too big, not too small. In my hands, the D7000 is a bit smallish. Now, admitedly, the 24-120mm f/4.0 is a stop slower, and doesn't offer the range provided by the three DX zooms above (however, FX' inherent lower noise floor can easily accomodate this one-stop difference with an increase in ISO). But, I already owned quite a few FX lenses, including an ultra-wide, AF Nikkor 14mm f/2.8, which is actually wider than the Tokina 11-16mm DX lens, when on an FX body. I also already owned the FX equivalent of the Tokina 50-135mm f/2.8 DX zoom, the AF-S Nikkor 70-200mm f/2.8 VR I.