Like never before? You mean with removable battery and SD card slot?
Looking at console replacement cases theres not much to do other than match up screw holes and the MICROSD card itself is done via a ribbon/super flat cable connected to A MICRO or normal SD port on the side of the replacement case, no need to rebuild the electronics since its just an extension to the MICROSD port. The replacement case would be a slightly different size but exterior size is not that big of an issue.
Anyone know if some 3rd party will make case bottoms with a SD card slot on the side via a simple cable?