I've been told today that internally Canon has bumped the 5D Mark III launch deadline ahead about 6 months. With the limitations of the Mark II as far as adding features via firmware (more on that in a second), Canon feels the camera needs an update to utilize the features of current dSLR's.
The email said we can rest assured that Canon will not be on a 3 year product cycle for the 5D line. The source went on to say the 3D is a myth, there are no plans for it currently. The 5D Mark III would get the full frame and 7D autofocus system and a better featureset for video.
720p & 60fps
A clarification. I'm told that Canon is omitting 720p and 60fps from the 5D Mark II firmware update. The firmware update will have the 24/25p update.
Before people start cancelling orders. I still think this is a late 2010/early 2011 camera and the rumor is CR1.