If you have a digital camcorder that supports passthru (connect the Wii to the Video IN of the camcorder, and the camcorder to the mac via firewire or usb) you should be able to do it as well....the only problem with this and the Elgato method is that you may encounter some lag when you're playing. You also may not get the full widescreen experience unless you got an HD camera or tuner device.
I used this method to record some videos I posted on YouTube when I first got the Wii...which explains why I sucked so bad at bowling
YouTube - Wii Sports Bowling Training
- the quality is great....the game skill, not so much.