to come on this rumor game also ( and allow you to blame me if you like to do so.... ):
i have heard from a big canon distributor before photokina the following things:
( he itself order some hundreds of 1ds2 before! photokina cause he knew for sure that there will no new model,- he expected a big run on the camera after photokina again and wanted to have enough in stock ).
1. no new 1ds2 at photokina ( go to openphotographyforum , there i posted that also 2 weeks before photokina ).
2. 1ds-mk2n next year at PMA. same updates than formerlywith the 1d-mk2, larger lcd etc.
3. canon goes to mf 2007 at pma or photokina,- which sensor size ever this will mean. sounds not unlogic to think in 30x36mm, although i think more in the actual size with 36x48mm and 33 mp,- they just need to stitch their actual sensor therefore.
for me the canon-mf thing has logic,- they made much more money beeing the technologic leader in 35mm digital than with the 1ds itself (same than formel1 for car manufactors ). and it becomes very hard to improve here the cameras more. even the 5d has in fact the same resolution, so also the nikon 2dx,- all other come closer and closer. hard to see here in35mm an visible improvement in terms of resolution without making significant better lenses.
so they would need new lenses in any case, it is not cheaper to develop them in 35mm than in mf,- mf could be a 2, lineup without putting the existing 35mm lineup to the 2. place.
i believe that rumor.
and the market could grow significant up again, many 1ds2 users would climb the mf way if there would be similar performance for a better price than now.
i know a p25 or p20 becomes cheap now,-
but compare honestly what performance deliver a 1ds2 or a 5d, and how problemless these canons do what they promise( no colorcasts, no magenta flare, really low hi-iso noise, fast shooting speed, great af, weather sealed, )........ it would be very tempting for many people to have similar features in a mf bodywith the canon simplicity and experience.