From an outside source
According to information received by [NL], early 2012 will bring a new model full frame DSLR to the Canon lineup. The likely name will be the 3D. It will bring about new sensor technology for the EOS system.
The 5D Mark III wouldn’t make an appearance on the scene until summer 2012. It will feature a modified version of the upcoming 1Ds Mark IV sensor.
As mentioned over at NL, the 3D rumormill comes and goes and has done so for a long time. Although, this does go along with the idea of a split in the 5D line and the amalgamation of the 1D/1Ds.
I wouldn’t discount this one completely, but I’d have some sea salt handy.