I have seen some options in this forum to use the Wii remote with Unity - such as the UniWii plugin,
but they all seem to require Unity Pro.
I just uploaded a video demo, which shows that you can get the Wii remote and Nunchuck working
in Unity Indie, without the need of a plugin. You can do this by using WiiFlash and U3DObject.
WiiFlash consists of a server and a library (both for Mac and Windows),
and U3DObject lets you communicate between a Flash and a Unity file through the browser in which you embed them.
Here's the link to the video, which first shows a simple demo and then the FPS_Tutorial.
Although I didn't use a sensor bar in these examples, WiiFlash does support up to 4 ir points.
The short video just shows that it is possible, it does not explain how to do it. If you like I can clean up and upload the example project ,