I doubt if these will be above $3k!!! With the D800 now out, I can see the 5DX being aroun $3200-3500, but I think the 5DMk III would be below that...probably around $2700. at least that's what I would do if I were a product manager at Canon.
And why is that.
Looks like the Canon 5D MKIII will have
Much Better ISO (25600 native versus 6400)
Video on par or better perhaps.
The only thing the D800 offers is large MP, which a lot of people don't want.
So compared to the current 5D MK II which sells around $2300 retail...
Much higher ISO
EXTREMELY Better AF
and not sure what other bells and whistles are in there, but AF, FPS and ISO are each big improvement areas.