I have been using the C# version of this library for basic 2D gesture recognition:
http://depts.washington.edu/aimgroup/proj/dollar/
It works really well. However since I'm a bit scared to tweak the math in it, whenever I need to change how it works a bit, I just filter my input before giving it to the recognizer. Maybe similar can be done for the wiimote, but the library only speaks in x/y terms, so I imagine it would need to be extended somewhat.