Garamond on 15 May 2009
The show is just a huge advertisement for the Pokemon franchise. I really don't think they'd abandon that for an even semi-serious type storyline. It's always going to be the same formula and people will grow tired of it. Especially if the formula repeats over and over and over and over and over and over again.
But the kids like Pikachu so he stays. And they need new Pokemon so people want to buy the new games, so the old ones always have to go. And I'm guessing the Gold/Silver re-makes will coincide with Ash getting back some of his Johto Pokemon or him catching some Johto ones that have new evolution in whatever the heck is after Pearl/Diamond/Platinum. They can double up on that advertisement with that.
