Sure wireless MIDI is awesome, but it still requires a PC if you want to connect your DS to your MIDI keytar, MIDI modded NES or whatever weird MIDI gear you might have. So far, the solution to this dilemma has been TheRain's DSMIDI. But unfortunately it requires some skill to build and only supports MIDI output.
Now, with natrium42's, DSerial it's possible to connect MIDI devices to the DS easily. This method supports both MIDI in- and output.
So, DSMIDIWiFi has now become DSMI (DS Music Interface) and supports both MIDI over WiFi and DSerial - whichever of the two is available. You can even use both connections at the same time, for example to use the DS as a wireless MIDI bridge.
The example apps are DSerial-ready now as well. The current version is a pre-release that doesn't yet support MIDI input via DSerial, which I will implement once I have the hardware.
NitroTracker will soon get support for MIDI Keyboards and other controllers connected via DSerial. Given sufficient demand, natrium42 can probably be persuaded to mass-produce the MIDI-cables for DSerial as well.