According to this article on wsj.com, it appears that Star Alliance will be seeing a very large jump in presence in Central and South America. It's been announced that Copa Airlines and Avianca-Taca will be joining Star Alliance.
Having flown on Copa on a few occasions, I have to say I'm pleased with this. Matthew can comment on his experience with Avianca. :)
So the next question is to see what happens if LAN and TAM complete their merger. Will they pick Star Alliance or Oneworld or will Skyteam try to lure them over to the darkside?