Create Digital Music links to DSMIDIWiFi, a homebrew application that lets the DS act as either a MIDI controller or a synth over the wireless link. For some people this will be genuinely useful, and of course it's always nice to have something else in your bag of tricks. If nothing else, I can see using this to play with plugin parameters in Ableton or Phrazor, and the DS is actually small enough it could be disassembled and integrated into an instrument or another casing. DSMIDIWiFi also has the ability to add pitch-bend just by wiggling the stylus, which could be really expressive. On the other hand, I don't think it'll be challenging M-Audio's new wireless MIDI keyboard anytime soon--it's hard to play notes polyphonically on a DS, and there's no velocity sense capability. So for experimental musicians--or live musicians looking for an extra, non-traditional interface--this software will make sense. For most people, it'll be a novelty, and not much else.
Either way, the YouTube video that Tob, one of the DSMIDIWiFi programmers and creator of NitroTracker, put together to show off the program is pretty charming. In the future, all software should be demo'd by genial Scandinavians.