There is just no way the R600 will be a foot long. It won't fit into anything but the largest of cases. ATI would miss out on a lot of business. I think the 12" is for OEMs (assuming it really IS 12").
Yeah but then again... ATI will miss out on a lot of business if they didn't use the standard connector from current PSUs, and it looks like they will require a special 8-pin connector.
Buyers will have to change their PSU or add an aux add-on GFX PSU. That might push many potential buyers to go with the G80, less hassle.