I would not be surprised if tornadus does not get roost as it would lose its typing completely.(it actually becomes a normal type)
Anyway, I just had this weird lightbulb go off about Kyurem's move Glaciate. It's Frozen World in Japanese...like what happens to Unova in BW2. Part of me hopes it's buffed when carried by Black/White Kyurem or maybe it has some other battle or field effect now (accounting for the weird effect number in BW). Meh, guess we'll find out soon enough.