Bolt the Cat
Bringing the Thunder
Pokecloud.
Store Pokemon, W/L ratings, friend lists/codes, and all your other fun statistics between games on the Internet. No more needing to buy superfluous hardware; if I want to send Pokemon or items from Pokemon X to Pokemon Quadratic Formula, instead of shelling out $150 for a used 3DS, it's just a matter of uploading the 'mons from X, then retrieving them on Quadratic Formula. A friend registered on one game's Pal Pad is registered on all the other games synced to your Pokecloud account, your W/L ratio can be synced between games on the account, plus the Dream World. Use the GTS site with the Pokecloud to make trades, and give an option to show Pokemon on the Pokecloud to other people. Want to start a new file on one of your games, but don't want to lose the Pokemon? Pokecloud's your guy; upload the 'mons, start a new file, then sync the new file to your Pokecloud account to retrieve the Pokemon. Possibly overly ballsy, but put Pokedex completion on the Pokecloud as well, and let synced games send and receive Pokedex data to your other games.
it'll never happen but it'd be cool
LOL at Pokemon Quadratic Formula.
But yeah, I agree that some sort of Cloud based Pokemon Box type game would be convenient.