Richie: It'd be nice to see what he's doing now that Ash is in Houen. Who knows? Maybe he went there too! (I don't think he stayed in the Whirl Islands that long)

Tracey: I'd like to find find out more about Tracey. Does he even have family in the Orange Islands? I mean he never mentions them. Then again, Misty doesn't mention her parents either...

Sakura: I mean, she went on her own Pokemon adventure so she must have caught some other pokemon by now. It would be cool to see how she's doing.

As for Pokemon; I would also like to see how Charizard trains. I've kinda wondered that before.