The recent Coro Coro magazine had a lot of information about Colloseum and also the first screenshots from Fire Red and Leaf Green, the new Pokemon games. About Colloseum we learn that it will be compatible with Fire Red and Leaf Green and we also learn that stolen Pokemon are “dark” and don’t like you very much (when playing as Team Snatch in Colloseum). As for Fire Red and Leaf Green all we know is that it will have improved graphics, contests, and a whole new (old) Kanto to explore. Your starter Pokemon can be Charmander, Bulbasaur or Squirtle. If there is any more information you shall know as soon as possible.
Source: Coro Coro Magazine