Daniel Gump has released an open source SDK for application development in the Opera Browser on the Wii. He provides access to the Wii remote functions, complete source and documentation. Thank you Daniel for contributing your effort. I'm looking forward to the great ET applications we can develop for the Wii.
Update: Some of these don't work so well for me. The "Wall demo" completely locks up the Wii requiring a power off to recover. The Ship demo won't start. Pressing A does nothing.