Personally I'm a bit annoyed. Not because of the characters hasn't grown the whey we "all" imagined but the way people respond into these things. The most of you seem to think that it's somehow bad that Cheren was made to be the first Gym Leader while it's not at all. That is a clear sign that he has grown from inside too.
If you remember, Cheren was all the time emphasizing power and didn't really seem to understand that it really isn't the key to win. But now as we see him as the first Gym Leader of Unova we can in this case make an assumption that he has finally understand that in order to win you need more than pure power. You need to have a connection with your pokémons and all sorts of stuff like that. And I myself can clearly see him talking about this topic before the player challenges him.
Later on in the game it's more than possible that he can be rebattled and then he has his sort of the real team with him.
And what comes to the tournament, I am definitely happy to see Giovanni in there. All the other Gym Leaders are good but Giovanni is different. His dark, mysterious and he surely will put up a good fight. ^_^ But personally I don't see for example Red returning.