I like the way you think there... If there is a mess of Zeiss lenses for Canon coming, which seems like the logical choice, I really cant think of any other mounts out there that they could come out with. 4/3 maybe but that would seem to require some serious retooling of their lenses, but then again they will have to do that for the Canon's also. I hope they keep the aperture rings most of all but also have a setting for being able to set the aperture in camera, kind of like the A setting on Leica 4/3rd lenses but more of an M. For M 4/3 they would have to completely redesign their entire set of lenses they are milking right now but whos to say in the future a few of the ZM lenses could not be retooled for such use as they are pretty much set up for that use already.
Mamiya is a small player in the amateur market, but a huge player in the pro market, so its not such a huge stretch, but still the line of lenses they are talking about here is their 35mm SLR line so yes, I think its going to be Canon. Contax or Leica R mount is probably not what they are thinking, Contax's already excellent line of Zeiss lenses coupled with my more preferred Yashica lenses making that an already very well rounded system, not to mention a dead end one. Leica R mount already has a spectacular lenses and a wide range from ultra wide to tele covered well. The only thing its missing is a more decent mid range zoom but that is just one hole.
If it is EF mount then I will stick to Canon and not make the jump to Nikon that I have been seriously considering more and more. While I like the Nikon bodies more, I highly prefer the couple of Canon L lenses that I do use, for instance the 70-200 2.8 L IS which is my fav in their line. If they retool the ZF lenses for EF mount, count me in, I will be looking for that 28 f2 as my first purchase.
ps. I have used that Zeiss 85mm in ZF mount a lot, its really awesome but the close focus is 1 meter, tisk tisk.