Usually these simple wii series work on both PAL and USA as far as I know. Haven't tested this release out yet since I'm not too sure what to expect and still too busy with Brawl, Fire Emblem, Mario Galaxy, Zack&Wiki and Zelda: TP.
It works, yes, but some textbox are empty. Menus and others are ok. Propably online works too, but I don't know because I have some problems with Wi-Fi USB Connetor. Vista + F-Secure + Nintendo Wi-Fi USB Connector = no good.