Here's what I want.
About 8...10 MP. Why? Because large sensels produce larger signals and this will improve the signal to noise ratio, hence allow higher ISOs, a'la the D3s *except* that Canon handles black better than Nikon and also doesn't foul up my images with noise reduction I can't turn off. Also, because an image of this size transfers faster, takes up less space both in the camera and on disk, processes faster, loads faster, saves faster, and also means the camera can shoot faster, and ALSO means that the available lenses will do an excellent job because the size of the individual pixels pushes diffraction further up the f-stops and doesn't require such tight focus to be pixel-accurate, either.
The *only* reason I don't own a 5DmkII is because of the 21 MP. That's ridiculous. My 50D, at 15 MP, is already making images that are far too large. My 40D was better; but the 50D's ability to shoot at ISO 12800 has me hooked. But I can't see going to 21 MP for ISO 25k (still, if it was in my hands... the wallet might be in danger.)
Other than low noise, high ISO, and hopefully an end to megapixel madness, I don't really care about things like AF - give me one good center point and I'd be happy; I *really* don't care about video; I'd like approximately the 50D feature set and that'd be fine.
Having said that, I'm sure they'll give me a plastic body camera with 50 MP, ISO 6400, and every video mode known in NTSC, PAL, SECAM and HD. And I'll have to stick with my 50D or break down and buy a 5DmkII.