Im planig to get the same. Now I get rid of my Canon equpiment and next step will be whit changing religion :)
Nikon D700 will do a bes for me and my needs. Camera is quite good at low light (high iso, even better than 5DMKII)
in whit very nice AF, precise and fast. Also, was very good point of geting a 70-200 2.8 Nikon Lens (the lens is quite better
as the same range Canon) and other thing – 2x extender on 70-200 will give you a more sharpness in edges
and AF will still be working