Tony's new partner, "The Sandman" is voiced by the same guy who played Manny in the movie (that would be Steven Bauer), and the narrator is voiced by Robert Loggia, who played Frank Lopez, Tony's backstabbing boss from the original film.
In fact, there's a lot of famous voices (and professionals, some from The Ocean Group, of all places) who are part of the cast. Sometimes as background pedestrians, cops or thugs, sometimes as minor characters, sometimes both.
Most bizarre of all is the cameo of Ahmed "Jar Jar Binks" Best in there... somewhere (the hotel receptionist from early in the game?).
Cheech And Chong appear in the game Cheech Marin is mob boss Gaspar Gomez and Tommy Chong is some random hippie you encounter at various locations in the streets.