It looks like the recent interview the New York Times did with Reggie Fils-Aime about the DS getting full game downloads from the Wii is false. The original goal was for Wii-to-DS downloads to limited only to demos and Nintendo announced today that those limitations are still what they have in mind.
A representative from Nintendo has stated that “Users can download games to play on Wii, and, in the future, the Nintendo DS will be able to receive demo versions of some DS games from Wii, but not the entire game. The demo will be erased once the Nintendo DS is turned off.” Well, that sucks. Oh well.