I don't know, the only DSLRs I've sold were my D30 and 1Ds. I could see myself someday grabbing a cheap but clean D30 out of nostalgia, but don't foresee wanting to use the 1Ds again. Meanwhile, if I want to go back to a previously owned model...I still own them, so I just grab one. Nothing like using a D60, 1D or even 1D2 to appreciate more recent models.
The truth of the matter is, a 5d sensor and A/A filter, coupled with an updated "platform", IE: better LCD, menu system, sensor cleaning, buffer, decent autofocus system and maybe live view and lens micro adjust would make it one of, if not THE best DSLR platform ever.
5D sensor + the bells and whistles of the 7D = gold.
Dont need/want the 5D2 with it's worse banding and identically pathetic A/F sytem
Nothing like using a D60, 1D or even 1D2 to appreciate more recent models.
started with FD glass and with the advent of u4/3 I use that FD glass often even picked up a few FD lenses along the way.