Well, if one thinks about it, the 3DS can read the header information for both DS and 3DS games/apps with the same interface, which could mean that data could be loaded on the 3DS by either method as well. Not saying 3DS games could be loaded via the DS protocol, as those games aren't designed for it, but perhaps homebrew could. It would be a matter of preventing the 3DS from going into DS mode when executing the game/app.