Thanks to holiday money, I finally have a chance to get a capture card! I'm not really looking for anything fancy here, just something inexpensive and easy to set up that I can record Wii U gameplay with. I'd prefer something that captures component video, but HDMI also works (the Wii U can be set to either).

the AVerMedia LGP is probably what you want, since it's OS independent, don't really know any that have drivers for mac.