Don't think a D700s will appear until a year after the D3s appeared - so probably later this year - any earlier would be a suprise.
However, Nikon will have some big announcements in early Feb.
Expectations that a camera announcement will be a D900, 18+MP (I say 18+ because it could be 24MP (D3X sensor) or 18MP (18MP sensor was prototyped along with 12 and 24 earlier) - leaning more towards 24MP because Nikon does like to reuse sensors if they can)
Some lenses too. Also, I've been hearing of a surprise announcement - though not sure what it is - guessing something to address the low-end DSLR market segment.