If you have the money, the D800 is exceptional. However, the FPS is only 4 on the D800 and the D7000 has 6 FPS. And the crop factor of the DX sensor on the D7000 will give you the longer reach for sports.
You are the one who must decide if you want to stay with a cropped sensor, or if you want to go with the FX sensor on the D800. You may wish to shop some of the FX lenses, especially all the "pro" lenses before making a decision. Certainly if your D80 is working, you may wish to hang around the forum and do forum searches, read the posts and see what folks are saying. You can always ask questions on the existing threads and many answers will be given.
The change in format is a big one. So at present, waitng to see what Nikon is going to give us in a high end DX camera may be the best idea.