A new device is coming out for the Wii that will allow users with a Nintendo DS Lite to charge their unit using the Wii's rear-end USB ports.
This is the first time that the USB ports for the Wii will actually be used. If you are a Wii owner, then you have more likely than not, never touched the USB ports. They kind of just sit there as of now. If you have ever been curious, and tried plugging in an optical mouse, you would find that the bottom light brights up, but doesn't do anything.
It has not been confirmed, but you can probably charge the unit by plugging it into a computer. As of yet, there have been no announcements for a North American release.