[Ben Heckendorn] put together this little beauty on engadget. It's not quite as over the top as the XBox 360 laptop, but there's a reason for that. He'll be putting up a How-To series covering the construction. If you've been pondering building a portable yourself, it'll be a nice jump start for your hardware hacking skill-base.
http://www.hackaday.com/2007/01/19/ben-hecks-wii-laptop-on-engadget/