We've been following this for a little while to let some meat stick on the skeletal rumours, and it's finally feeling substantial enough—though definitely still a rumour—to throw your way. It looks like Nikon's got a 41-megapixel medium format (MX) sensor up its sleeve, which is most likely for a digital rangefinder. Nikon itself teases something BIG for the Wedding & Portrait Photographer International convention in Feb. in the pages of Rangefinder magazine. Finally, Nikon Watch has a tip (albeit unsubstantiated) that the MX format sensor is 48x48mm and in fact 48MP, and will go inside of a digital rangefinder that's "not to [sic]dissimilar to the older film Mamiya 6 camera philosophy." There's more.
Obviously, a new format means you'll need new glass. But, the tipster says that the rangefinder will be able to use DX and FX lenses with a mount adaptor, giving you crop factor of 1.5 for the DX, 1 for the FX and 0.5 for MX lenses. When shooting with FX,you'll be able to rotate the sensor crop from landscape to portrait instead of having to turn the whole camera, and somehow you'll still get to shoot the full square resolution. And yes, this thing will have live view. Given Nikon's penchant to leak like the Titanic, we'll know more about this puppy soon, no doubt. [Nikon Rumors, Nikon Watch - Thanks Peter!]