Below is an update of the current state of rumors surrounding camera bodies. Most of what's below is opinion, or clarification of what's going on.
1Ds Mark IV
I was told a long time ago that a 1Ds Mark IV (or similar) camera would not arrive until late 2011 or early 2012 and would be 40+ megapixels. It would be a “big departure” from the current 1Ds line.
There's been no information on the line that I'd call factual yet, the information I have been told seems to lead to a new type of camera on top of the Canon lineup.
1D Mark V
We've heard a lot about the amalgamation of the 1D/1Ds line over the years. It's been a lot stronger in the last 6 months. It was over 6 months ago that I was first told a new 1D would arrive before any 1Ds replacement.
I personally think most spec lists recently have been wish lists more than fact, however I post them anyway just in case. I suspect we'll have better information in the coming week or so.
All signs point to this camera, more than any other.
5D Mark III
Everything I get now says it's a 2012 camera. Most likely in the February timeframe.
There's a lot of rumblings about the line splitting into 2 models, nothing concrete though. If this camera was coming this month, I believe we'd hear a lot more about it.