At first, I was worried because now neither device was responding. After double checking power and data connections, I logically figured out the problem was switched SCL and SDA lines. What had thrown me off was the fact that the Gigaware nunchuck board is mislabeled, with those two lines switched. I did get it working in the end, though.
Now I have a nice and tidy sensor package with convenient mounting holes, ready to be put into use. As a bonous I also get 4 buttons and two 2-axis joysticks.
this $60 product, no offense Sparkfun...) [$36 if you count R&D for the Nyko Nunchuck...)