I respectfully disagree. If the fresh Nikon rumor is any true, there is not much what is left to offer for a new 1Ds - let's suppose for a moment the upscaled 1D being FF and 27MP. Now, for a 1Ds that would require a lot more MP to make the difference, but current lenses might not keep up with such a density, plus an FF with 27MP (1.3@16MP upscaled to FF) would fulfill majority of user needs, taking away many former 1Ds users, whereas the market for the 1Ds is already quite small.I don't think the 1Ds and 1D lines will get merged ... pretty much ever, since they are different cameras that do totally different things. Look at Nikon, they have the same differentiation in their top cams, between the -x and -s models. it exists for a reason.
I see your point Ivar, but I disagree about the lens vs pixel density aspect. Canon's made no secret of the fact that they believe their newest II-series lenses to be able to resolve well into the 40-50 MP range ... in which case, a 1D camera could be in the 20+MP range, and a 1Ds camera could be in the 40+MP range. definitely a pretty big gap there still. and I think, for studio and landscape shooters that are looking for cheaper, more manageable, more travel-friendly alternatives to medium-format cameras (macfly comes to mind), Canon does need to get up into the 40-50 MP range to have a competitive product. upscaling a 27MP image isn't going to cut it.
they will have to very shortly come out with new wide and standard primes to match its revamped telephoto lineup.