All children, except fake ones, grow up.
Fake ones, like Charlie Brown and Richie Rich, don't have to. They can be children forever. I think that's what we like about them. Calvin will always be a 6-year-old boy testing the boundaries of imagination with his stuffed tiger, Hobbes. The Family Circus will always comprise two adults and four children (and PJ will never, ever talk).
In real life, you can't trap someone in childhood, no matter what. Time ultimately catches up: the 13-year-old and 11-year-old I met a few years ago, the ones who went with me and their mom to Busch Gardens to brave the 90-degree drop of Shiekra, they remain 13 and 11 only in memories and photographs.
And fictional characters aren't immune to aging. Arnold and Willis Jackson eventually become Gary Coleman and Todd Bridges. It's inescapable. No one cared much what the Beaver did as an adult, or who the Brady Girls married, or where Zack and Slater went to college. And don't even get me started on what happened to the Little Rascals!
Now Mattel and Nickelodeon want to prepare us for a pre-teen Dora the Explorer. Forget the hysteria of the blogosphere on this one: she's not Dora the Tramp or Dora the Streetwalker. She's a 10-year-old girl now, in a new incarnation that will be available in toy stores this fall.
Sometimes the aging of comic or fictional characters can be delightful. I loved the idea of Peter Pan growing up to become Robin Williams. And it was great watching the kids of For Better Or For Worse go from toddlers to spouses.
So is this new Dora a good idea? I don't know. Some marketing guru somewhere thought it was a good idea. And marketing gurus never make mistakes, do they?