I was talking with a regular source and all indications he’s receiving is that there will be no 1Ds Mark IV or replacement of the 1Ds Mark III in 2011.
There is going to be a very big departure in the high end from Canon.
The 5D Mark II took from the 1Ds3 market in a lot of cases (not all). A replacement of the 5D Mark II would do the same if they kept the status quo for a 1Ds4 upgrade.
I hope to hear more soon.