I think it is only a matter of time before National Teams are added to the NBA Live series. NBA Live 2004 included the Spanish National team (technically only for the Spanish version of the game) and NBA Live 2005 will include an International All-Star and a Euro All-Star team.
NBA Live 2004 also contained references to Argentina, Australia, Brazil, Canada, China, Croatia, France, Germany, Great Britain, Greece, Italy, Japan, Lithuania, New Zealand, Puerto Rico, Russia, South Korea, Spain, Turkey, USA, Venezuela, Yugoslavia in an unused DBF file...so we can see that EA is at least considering the idea.
EA's NHL series has had international teams for years and for NHL 2005 the are including the upcoming
World Cup Tournament in the game. Having international teams in the game has never detracted from the NHL part of the game...