The last days there are rumours at the Wii Forum of Nintendo Japan. From some reaction, Wii SPorts 2 , which is in development, is a huge success.
Wii Sports 2 would have, beside the 5 original games, also basketbal, swimming, horseracing, hockey and volleybal. Also Wii SPorts 2 would have online fuctions. So you can play against European, Japanes or Amerikan people.