It took quite a while for Playstation Move to get a proper name (Wand? No. Arc? No. Fiddlestick? No. Move? Yes.), and now the second part of the controller - so far known as Sub-Controller - seems to be going through the same motions (aha! See what we did there?). Engadget has found a new name registration, and it seems like it will be called "Navigation Controller" from now on.
In reality, I guess we'll all keep calling it "nunchuk" anyway. Sorry, Sony.