I can't help but get the feeling a landscape oriented 1D is in the works. Of course, if the medium format rumors are true then that would be the answer.
I have zero interest in a MF Canon and very little interest in a >25mp 1 series, for my uses a 25Mp 1Dx MkII would be the perfect camera, I certainly don't want less mp than I have, I regularly print with my smallest size being 16" x 24" and my largest standard print at 24" x 36" but I have no desire for excessively higher mp and the processing and storage that their regular use requires. I am a generalist and mid 20's suits me personally absolutely fine.
Right, you have no interest in more detailed pictures, which may be understandable given how good things are right now. I agree that moving to high megapixel sensors won't be a gamechanger IQ wise, but it will be better. At the very least you might appreciate the benefits after downsampling.
Medium format does change the game though, and the resolution will definitely be warranted there.
I never said there isn't a market for high MP 135 format cameras, and there certainly is for MF digital, but I am not in those markets. I still, occasionally, shoot 6x9 film, but whilst the end results are undoubtedly "better" the time, hassle, effort and expense are, in my market, not worth it.
It isn't that I would object to more detail, but it is a never ending cycle that begins at getting a new body, you then need the newest MkII lenses, you need adequate support (bigger tripod sturdier head), you need bigger cards, you need faster computers, hard drives etc etc (people that say storage is cheap are underestimating all the other incidentals) ultimately you end up changing almost everything you have for a percent or two of additional detail, add in the extra time and care needed at capture, and the additional processing time for the bigger files and something has to give. I have made the business decision that I, and my customers, are not in that market, neither of us will benefit from "more".
Others are in that market and will embrace the new cameras.