Following the news that Nintendo would again partner with Gamespy to set up the Wii's online gaming structure this year, a Wii fan site spoke with a Gamespy rep and heard something bad: namely, that friend lists inside Wii games will be seperate for each game, not unified to your already-existing Wii friends list:
Ew. The first online title in the US will be Pokemon Battle Revolution, coming June 25. Hopefully Nintendo will work out a better solution, or at least allow you to individually import friends from your Wii master list. Because if not, this bites.
No unified gamer tags or codes for Wii online [Wii: Definitive Speculation]