The big question is what body will this be in.
I'm sporting the 1D-X and the 5D3 was tempting (but some features only a little better and negatives were big for me) but I prefer the series 1 bodies and features. However, I would have loved a big step up in megapixels in my 1D-X.
I'd prefer rebel size. Yes, seriously.
There is no need to feel like a overpacked mountain donkey while hiking / traveling for landscapes.
My shoulders says no! .. After all, a high MP body will surely be aimed at landscapers and travelers.
But yeah, it will probably be a 1D-type body, just so that Canon can charge extra for the "pro size".