I know for a fact the the NHL in America has a larger audience than both college basketball and the NBA. The expansion of teams into southern cities has helped some with that but I still think Canada could hold nine franchises with the two additional in Hamilton and Quebec. The NFL and MLB are still America's two favorites but the NHL has made great strides in recent years. I also think that the fact that they share arenas with NBA teams means that many more people will at least attend games or keep up with the team.
Nothing is set in stone. Hansen wants a guarantee from both the NBA and NHL that Seattle will get a franchise before he builds. It will take three years before the arena is constructed, and David Stern isn't about to let the Sonics play in the old Key Arena for three years. Seattle Hoping to Erect New Arena