An interesting article on his website actually pointing out that Olympus and Panasonic have been successful with their 4/3 cameras which offer adapters for most other lens mounts. And so perhaps Sony should be trying the same with the NEX cameras when they are released.

I'm not sure how many Alpha users would buy one, (an A850 with a Nikon lens mount), not many is my guess. But according to Thom (and I agree), there would be thousands of Nikon system owners who would buy one.
It would be a daunting task though, the camera would need the Nikon lens database onboard, including all the individual lens chip compatibility and encoding etc. and then there is system flash compatibility, the i-shoe would most likely have to go as well. Also there would need to be some system changes made to accomodate VR so it would work properly, and an either/or choice with SSS.
Greg