The Nintendo Wii has never really been friendly to independent developers.
To get a development kit you need to shell out up to 10k, have a leased business premises, and have your game already in the prototype stage, none of which are practical for an indie dev.
This is a great shame because it is a very unique platform allowing interesting user interactions.
The Wii Homebrew scene has succeeded in using various exploits to load and execute unofficial software on the Wii, notably allowing some models to play DVDs which is not normally possible. Unfortunately running such software requires an exploited Wii and so is not exactly a mainstream alternative to traditional publishing.
Fortunately for us, Ryan McGrath has spent time working out the kinks in the Opera web browser contained in the Wii system software and has abstracted interaction with the controllers to make writing web apps for the Wii much easier. The code is on his GitHub account and I suggest you check it out. The most interesting thing is that all 4 controllers can be used concurrently, enabling some multi user web interactions that are not normally possible with a keyboard and mouse pair.
Unfortunately for us I don’t think anyone as yet been able to access the sensors on the 3DS from inside the browser, nor use any of the 3D functionality. We can hope for access in a firmware update but knowing Nintendo I wouldn’t hold my breath…