Hi there,
think there will be only one 5D X in the future maybe end of Feb. but don't think they will come up with a "good weather" camera like Nikon D-800 with high MP and workable Iso :-)) from 100-1000 ;-). The next Body after the 5D X maybe in autumn with other Specs.
Personally don't like the blown up Sensor design from the nikon D-800.
This will be the new 5D X, the new name for the MarkIII
specs like this ;-)
22MP maybe some more

?? but not to blown up
61 points AF (Similar to the 1DX but simpler)
4.9 fps, ISO 100-25600(50-51200)
1 Digic 5+ and maybe + Digic 4
price range 2500-2900 USD