I have a D90 and felt like you when I saw the D7000.
I ended up waiting and got a D800.
The decision was partially made because I wanted to upgrade some lenses as well.
From what I've heard about the D600 looks to be an excellent choice as well.
The file sizes of the D800 has me shooting it more like a film camera than digital
until I work out a good storage solution. I am enjoying it for sure though.
Free Pussy Riot.