my guess is the answer to these is actually fairly straightforward.
regrading the unified sensors: yes, because it is simpler and cheaper. and honestly there's no reason to have a whole bunch of nearly-similar sensor resolutions, I'm sure pretty much everyone would prefer canon spend its energy focused on just 2-4 sensors rather than mucking about with a dozen. in fact, that's one of the key complaints about the APS-H sensor used in the 1D Mark IV, is that it is consuming R&D resources that could be better dedicated to a universal FF sensor used across the canon lineup. in terms of differentation, there are plenty of other ways to differentiate cameras that are far less costly (limiting frame rates, movie implementation, prism size/type, weatherproofing seals, etc.). actually, pretty much any of the above are far cheaper to implement than developing additional sensor types.
I think everyone is pretty much expecting >21MP out of the next FF sensor, so ... yes. but again, I don't think the primary differentiation is the MP count, it's the quality of it. people are paying for a FF sensor when they buy a 5D Mark II over a 7D, not because they desperately want 3 more megapixels of resolution.
I hope (and expect) that canon will retain CF cards for their professional lineup. in terms of build quality, SD cards don't come close to CF cards, and when you're serious about the photography that does make a difference. the performance of CF cards still remains slightly ahead of SD as well (to my knowledge, I could be wrong on that one). also, SD cards have exposed contacts, which is just not reassuring if you're shooting and swapping cards in difficult locations.