The Wii can handle just about anything, Mop_it_up. The Wii's internet Browser, well, can't.
It's an issue with memory, in most cases, and half a gig, when you take out what's used for saves and game data, doesn't really cut it. It would work better if they used something like an SD card to hold the buffer.
The Wii itself can play DVD quality media, like movies and video files, you just have to give it a method to do so :/