I really doubt that RX-51 will have fullsized SD, cause it's rather big for a pocketable device with such high "technology-per-inch" score. I think it would be nicer to spend available space on the battery, than on fullsized SD. I have CF in my camera but I don't ask anyone to build it into the device cause I'd better see good USB-Host implementation to transfer data from any device I want, not only Sd, ms, cf, or xD.