This is really disappointing, to be honest. I always liked both characters. I used to watch "Da Ali G. Show" reruns with my buddies in college. "Borat" was one of the funniest movies to come around in a decade.
Cohen says that their time has come and passed, and he's moving on. I'm sure he'll one day revisit those now-legendary comedic characters, but I think that Cohen should also be applauded for moving on and pushing forward with his career.
Cohen is quickly becoming part of the top ranks of comedic actors. I thought he was really hilarious in "Talladega Nights" as Jean Girard, the homosexual French rival of Ricky Bobby. I have also heard that he is a riot playing the character of Pirelli in "Sweeney Todd", nearly stealing the movie from Johnny Depp.