The hits keep on coming.
It has recently been suggested to me that there will not be a 1Ds Mark IV at all.
The 5D Mark III (or whatever it's called) will be aimed to take over the market for 1Ds users.
I know a couple of 1Ds3 users that are using 5D Mark II's most of the time now. Both folks say if the 5D3 ups its build quality and AF, they'd never buy a 1Ds again. If it's priced at under $3000, a lot of people will probably feel the same way.
The same person says it's possible that a new camera at the top of the lineup aimed solely at the medium format market, but not a medium format camera, will come to fruition. The design will be a radical departure (possibly modular).
We've heard rumblings about this in the past.
Canon fans say all the time that they want Canon to be “revolutionary again”. However, when a rumor points to a big departure (which doesn't happen frequently), it's generally put down for being untrue or unrealistic.
I have a lot of trouble seeing a point to the 1Ds line as its currently implemented, I'd say a radical departure is a strong possibility.