Here we go. We'll probably see new CR1 rumours of a high MP camera until, well, until we actually get one! Like I've posted elsewhere, I just can't see Canon introducing a 30MP+ FF camera with the same IQ as the 5D3 for anywhere near the price of the 5D3, unless they cripple other aspects (pro AF, FPS, build). Could the "entry level FF" everyone seems to be clamouring for - after Canon put the 5D3 just out of reach for cash-strapped enthusiasts - be a 40MP monster with very basic functionality? Unlikely.
I think the key word here is FF. I can see Canon pulling a rabbit out the hat with a 30-40MP 7D II, similar specs to the current 7D, lower high ISO IQ than any of the FF cams, but decent low-to-midrange IQ and best-in-class resolution. That way it doesn't step on any "pro" toes in terms of ultimate IQ/build, and undercuts Nikon's high-res cam by $1000 or more.
Personally I'm happy to wait for a 5D Mk IV with 40MP, an extra stop of juice, and a new DiGiC 6 keeping the FPS up around 6. Hopefully by then 128GB CF/SD cards would have dropped in price to affordable levels, and Intel would have cranked out some CPUs capable of dealing with the 100MB+ RAW file sizes (my head hurts just thinking about it). Until then two 5D3's will do the business, literally.