[DarkGardevoir]

I believe Buneary won't evolve. That's just me, obviously, but Buneary is just too cute :P

I don't think Monferno should evolve. I don't really like Infernape in general, but I think Monferno is good enough as it is (and besides, similiarly to Buizel, it wouldn't gain much upon evolution)

Grotle... meh, I don't really know about Grotle. Despite I choose Turtwig myself in the games, I don't know what to say about this. It really is a Bulbasaur rip-off in my opinion, the only difference being the vines and the fact Grotle evolved. Since I doubt Ash will switch teams before the league, I hope he'll take it out in the filler saga.

Gliscor is too fun <3

I've yet to see how Staraptor acts, so I can't say anything about it- but, it being Ash's mean of aerial research, despite whatever you may think of Gliscor, I highly doubt he'll leave it at Oak's lab.

I think Ash should get an Ice type. I don't know, he only owned one so far, I think it'd be only fair of him to get another. Too bad the Ice types are few and far between- and considering Paul has Weavile, Dawn has Mamoswine and Candice owns Snover and Abomarsnow, I don't know what he could get anyway. I really can't see him owning a Froslass, and he already has Glalie anyway.

As for Dawn's team, I guess that the Leafeon would be the most obvious choice, depending on when one will have its anime appearance. It would be interesting if she got a Bug Pokemon to take care but then again, I dunno.

And in the filler saga, I hope Dawn catches a Cyndaquil <3 I think it'd fit her.

Can't say much about Brock either, I think you covered it well enough. If Hippopotas came back and went with Brock it would be a nice add, but I don't think it's gonna happen. Besides, Brock will probably only take care of baby Pokemon