Leave it to an enterprising Apple developer to come up with a solution that the big guys either can't (or won't) find. Manton Reece of Riverfold Software has developed Wii Transfer, a small utility to allow streaming of audio (mp3's or non DRM'ed AAC files) and video to the wii from your Mac on the local network. The videos are converted by the software first to FLV, and you won't be able to watch HD (hey, write to Nintendo!) but if you have one console, and its the Wii, then this is a solid streaming option. Heck you can even move your Miis over to the Mac. Why? Because you can!
Here's our talk with Manton at Macworld: