If the 5DIII and 1DsIV will use the same sensor and the 5DIII improves substantially on the 5DII's shotrcomings (mainly AF), I would bet the 5DIII will be released a year or so after a 1DsIV, so the two will be differentiated by time. If they are temporally close, or the 5DIII is released first, there will have to be a BIG feature gap, and I suspect that will mean a crippled 5DIII rather than a super-enhanced 1DsIV.
So, which would people rather have?
1) A 5DIII that uses the same sensor as the 1DsIV and has a much better AF system than the 5DII, but is not released for over a year after the 1DsIV?
2) A 5DIII that offers a couple more megapixels than the 5DII, a slightly better AF system, and maybe 0.5 more fps, and is otherwise the same in most respects as the 5DII, but comes out this year?
While I agree with most points you all have made I think these are the central points.
Canon's issue is that they will absolutely sell more 5DIII bodies and cannot afford to lose them. At the same time they cannot further mess up their market segments. As noted, Canon also still needs to find a reason to make someone pay $8k for the flagship.
I agree the 1D(s) bodies will be first, but they will lose all the market momentum especially if Nikon drops the D800 soon. The D700 was stiff competition for the 5DII already with regard to pure stills. The 5DII sold as well as it did because of video. I think if Nikon adds nice video in the short term, then Canon may well lose many sales.
We seen to all be making the assumption that Canon needs to sell lots of 1Ds bodies. That may indeed not be the case.
Another view of things may be that Canon needs a flagship studio body that satisfies a small niche and provides bragging rights, and a popular full frame body that makes all the profits. 5Dx
bodies sell many times more than the volumes of 1Dsy
bodies. Canon needs to sell lots of 5Dx
bodies in order to make a profit. Canon needs to sell a small number of 1Dsy
bodies in order to hold a small number of leading light photographers who influence the masses and a small number of busy pros who have very demanding needs.
I don't think a lack of differentiation between the 5Dx
necessarily hurts Canon. It could even all be part of Canon's plan. After all, the 1DsIII has proved to be a niche product and the 5DII a huge money spinner. That has been a success recipe for Canon.
Maybe Canon does not need or want to sell large volumes of 1Ds bodies - which would especially be the case if the margins are low. Even if Canon could sell a few times as many 1DsIIIs as they are, they would still not approach anything near the volumes of 5DIIs sold. I would thus suspect that the margins on the 1DsIII are much lower. (Here I mean the margins for Canon, not for the channel.) Thus, it may make a lot more sense for Canon to focus on making the 5D series a success, even at the expense of 1Ds sales - which would especially be the case if the margin on the 5DII is better. Given volumes and the lower tolerances and build quality of the 5DII, I suspect that is the case.
We are all quick to assume that Canon are kicking themselves for cannibalising 1DsIII sales with the 5DII. We may be wrong. Canon may have achieved exactly what they set out to do.