A d4 (I'd accept a d400 tbh) with a more accommodating (and universal, electronically) lens mount (lets say a 28mm register).
The d4/d400 may come soon (more likely than a d800 IMO), the rest, not so much.
Edit: Realised I had the register distance the wrong way, an ideal universal mount would have a short register, since longer registers can be accounted for with an extension tube on the adapter. 28mm would only exclude a handful of fairly rare mounts that aren't really worth worrying about, the only 'common' mount that would be too short would be Leica M bayonet at 27.95mm, but that 0.05mm probably wouldn't be a big deal, and assuming we have a nice wide throat on a universal mount, then you can probably recess ever so slightly anyway.