A Wii Jockey is someone who has mastered more than one aspect of gaming on the Nintendo Wii.
Someone who is good at a single game but sucks at everything else does not qualify for WiiJ status, only true multigame masters qualify for this title.
Girl #2: My man Peter sucks at the Wii, you should play him sometime.
Guy #1: Haha whipped your ass at tennis too, I totally rule at Wii Sports!
Guy #2: Yeah but you're no WiiJ, I'm still the master of other titles.