There will be at least four new characters added in season three, two men and two women, none of whom are American. This goes hand in hand with the storyline expanding internationally, which probably won't be much of a surprise to fans, given the events in the final episodes of season two, which are airing now. Casting for these new characters will probably begin in May. Scheuring noted that, "The scope of the show will play on a much more global scale."
As long as it's as good as this season, I'm more than happy