I'm guessing that the rotation is going to be CoL-On. The change in ultra rares is a pretty large indication. Pokémon likes to rotate 4 sets at a time, remember the rotation to MD-on? The reprinted a bunch of cards in Call of Legends that Pokémon feels are healthy for the format, Dual Ball, Cleffa, Oak's, Ninetails etc... Black and White on makes less sense in my opinion because then we wouldn't have a solid way to search out basics. All of that would have to be done with Ultra Ball and Level Ball. This would mean the format would be a lot more luck based, it'd depend on what you draw.
VETERAN AUTHORITY BETTER THAN THE MAJORITY