I remember reading an interview with Marc Brown--I think it was in Parade Magazine, but I'm not sure--that Brown said Arthur would always be an 8-year old. That's too bad because I would so like to see a series of Arthur as a teen. I wish I could find the article!

I was picturing a live action movie where the characters are human. Actually, I was picturing Arthur in college, D.W. in high school, and Kate in junior high. Perhaps an all-star cast?