A few days ago the New York Times reported that the DS will be able to download full games and demos through the Wii in the future.   It seems that they confused WiiWare with being able to download demos to the ds.

An article about the Nintendo DS video game system in the Dec. 31 Business Day section of the New York Times incorrectly referred to future capabilities of the device. The statement that complete Nintendo DS games will eventually be able to be downloaded into the device via a wireless connection with the company’s Wii game console is incorrect. 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.

Source - Kotaku