Exxxx-cellent. Fox has ordered two more seasons of The Simpsons, already the longest-running show in primetime television history. The 44-episode renewal ensures the series, currently in its 20th season, will eventually reach an astounding 493 episodes. How much more punitive chalkboard writing can Bart endure? Not bad for a primitive cartoon that debuted as a gap-filler on The Tracy Ullman Show back in 1987.