Upload & Sell: On
Personally, I'm planning to use my D800 for wildlife. When I went from a D3 to a D3x, I discovered I really liked the extra resolution. Not only was I capturing more detail, but I also had more headroom to crop if needed.
The only drawback to the D800 I can really see would be for birds in flight - 4FPS is maybe just ittle slow if you're trying to catch a wing beat that's "just right". The buffer is not even close to a match for the D4, but it's not terrible (17 in lossless compressed RAW I believe). For static animals, D800 all the way for in flight or active, I'd probably prefer the D4, but it all depends.
The nice thing is the D800 looks to have pretty sweet high ISO capability, the only real drawback to the D3x.
As for which one, I'd probably favor the D800 over the "e" version. Not sure if feathers might cause problems without an AA filter.