This is a little sad. I just found the track listing to Al's new album over here (right side of the screen, if you can't find it), and I don't know that I've heard a single one of the songs he's parodied. Possibly American Idiot, although I don't recognize it from the title. Guess I'm old or something.
Al's said that the first single will be the Chamillionaire parody, which we now know to be titled "White & Nerdy." Oddly, it seems to be available for listening on Chamillionaire's MySpace page. Guess he's got a sense of humor.