Are you impressed with Mega-Abomasnow?
I can't say, sadly, as I personally haven't had any chance to try it out. Though, its regular form is pretty great in itself, as it's able to whip hail and whatnot, which is very helpful, especially when utilizing moves like Blizzard. Its mega stats seem to be great, and ability is also nice; if they were all to be put together, I suppose it could be even more powerful. Its design, however, looks absolutely stunning!
What ice-type do you want to see a mega for?
Froslass would be pretty cool. Its alternate evolution, Glalie, wound up getting a mega-form, so it would make sense for Froslass to gain one as well. Aside from that, Delibird would also be nice. It's based around Santa Claus, if I'm mistaken, so in its mega-evolution form, perhaps they might be able to have it extends its belly and grow white beard around its neck, to have the Pokémon resemble him more?