Every good superhero needs a good supervillain--it's rule number one for making a good comic book, television show, or movie about do-gooders in tights.

Going by that commandment, Smallville writers are having to go back to the drawing board to make the show's star--a teenage Clark Kent, aka Superman--better by making some someone else badder.

Michael Rosenbaum, who has played arch-nemesis Lex Luthor to Clark since the beginning of CW sci-fi drama Smallville, is officially leaving the show. The move isn't entirely a surprise, as reports surfaced a few months ago that Rosenbaum would not continue on as a regular cast member (along with starlet Kristin Kreuk) but may make guest appearances.

Smallville's executive producers (Darren Swimmer, Todd Slavkin, Kelly Souders, and Brian Peterson), the CW, and Warner Bros. Television released the following joint statement regarding Rosenbaum's departure:

"It has been an honor and pleasure to work with Michael for the past six seasons. He is one of the best actors on television and has never failed to bring a new layer to the character of Lex Luthor in every episode. While Michael won't be a series regular and we won't have the pleasure of working with him on a weekly basis this fall, we like to think that we haven't seen the last of Lex Luthor. Stay tuned."

Classy guy that he is, Rosenbaum also released a statement to Smallville fans:

"Well, it's been seven wonderful years. Your support is what has made Smallville so successful, and I appreciate you all more than you know.

That being said, it is time for me to start the next chapter of my life and career. I hope that I gave you some enjoyment over the years, and that you found my portrayal of Lex Luthor to be satisfying. I am truly grateful, as Smallville fans are the best fans out there. I sincerely hope that you will continue to follow my career through my hair growth period and beyond.

I'm very excited about what the future holds, but certainly, Smallville will always be a part of me. I will definitely miss the greatest crew in the world, and the wonderful cast that has been like a family to me.

Thank you Al and Miles for creating the show. Thank you writers, producers, directors and editors. Thanks Tollin, Robbins and Davola for being there for the pilot. Thank you Peter Roth for employing me for ten years. Lisa Lewis, I miss you already. John Glover, thanks for helping me feel more comfortable touching other actors, while acting. Bizarre, but helpful.