^Vaporeon will definitely get used more when it gets Hydration, but I highly doubt that it will go Uber. Remember that reason Manaphy was promoted to Uber wasn't just because of Hydration, but more because of its great BST, access to Tail Glow, good special movepool, all in combination with Rest/Hydration strategy.
I agree with Espeon and Entei going to UU or higher. Espeon is good, but now Entei is a monster. Entei's main complaint was not having a physical STAB to work off of. Now it has not only Flare Blitz, but Extremespeed to boot. It's got to go at least to UU, if not OU.
And as a last note, I believe that many of the Ubers that were banned during the DPPt era will be brought back, if only for a short testing period.