RJM
Don't Worry, Be Happy!
The D7000 is the best DX Nikon yet. It does pretty much everything the D300s does and then some though I am not yet confident about its AF speed for birds in flight. It also shoots 14bit RAW files MUCH faster. I wish it had an AF-on button though as I have grown used to it on the D300s. But all the latest Nikon supertele's have it too so I could adapt. Bottom line if you want a new DX partner for your D3, the D7000 should be your choice over a D300s.