I don't want to dampen anyone's enthousiasm, but a patent is not the same as a product.
Even though sometimes a patent can indicate that a product is coming, its primary goal is to protect an idea or technology. Though it shows a digital back and an ordinary SLR, it goes into detail about how to adjust sensors to the image plane, and then protect them, and that seems to be the core of this invention. That's applicable to DSLRs too (the AF issue of the D800 comes to mind)..
Or, it may be that Nikon wants to offer replacable and opening backs on their future DSLRs to allow swapping AA filters, UV/IR blocking filters, different sensors.. But it's also possible that this is not intended as a user feature; a back that can be opened only by a repair facility to make product recalls less expensive.. who knows?