I'm inclined to suggest D7000 given some of the topics being discussed here in this forum - namely the image quality should be better and the focus may be near as good (or possibly better).
My own plan is to demote my D300 to second fiddle, with the D7000 taking the lead role in my wildlife shooting. We'll see how it goes but I don't expect to have a definitive answer until I've been shooting the two cameras side by side at least a month (approx end of November).
In my own wildlife shooting I very often find D300 ISO 800 critical in getting high enough shutter speeds. I am hoping D7000 allows me to step this up to 1600 enabling me to get better images at equal ISOs and higher ISOs when I need them. I will confess that I plan on getting a D400 too to replace my D300 but that could be a full year down the road.