The RPG creation game with a very appropriate name, RPG Maker DS, has just raised the bar on itself. Famitsu reports gamers will not only be able to share game data locally, but also online via Wi-Fi Connect. You'll be able to swap the smallest of things, like items and monsters, right up to full games. Now if that doesn't scream replay value, we don't know what does.
Of course, this news really only affects Japanese gamers, as a localization isn't that likely. Still, that's not to say there isn't any hope you'll be able to play the thing, especially considering that there's already an English-speaking community established for the game.