I feel this is one of the most important homebrew things that could be developed for the 3DS. In the sense of backups, you would no longer need a big SD card. And with the new 3ds' external storage now effectively "internal", it seems like this makes a lot of sense. Instead of backing up all your gameboy, gameboy colour, gameboy advance, genesis, nes, snes, ds and 3ds games to your 1 SD card... You could retrieve them via bittorrent when you want to play them. You could access them through a glorious custom menu, with a search box. Besides the 3DS games, most games would be finished downloading in less than a 1 minute. It could be a totally seamless experience. If you kept your games over the network and not over the internet, then even 3DS games would load super quickly. There's a lot of potential... But do you think it will actually happen? I was surprised no one made a bittorrent api homebrew for the Wii, because similar goodness could have been done there.