White Kyurem's on the site now. Since there's no topic for it but it's part of the theme decks, I'll post my thoughts here:
I'm quite underwhelmed by it. For a basic it's of course great, but we've been spoiled so much by basics this is quite "meh". Its first attack will quite likely deal only either 0 or 20 damage (anything else requires tons of luck), and 80 damage for 4 energy is nothing special either, not even with its 50/50 chance to deal 40 damage more (especially not when considering requiring 2 different colors is stricter than usual). And especially not when considering it's White Kyurem's only "real" attack.
EDIT: And I see Black Kyurem's now on as well. Its first attack is better (White Kyurem needs 3 heads in a row to be better, and Black Kyurem is more reliable since flipping tails on the first coin flip still allows the second coin flip to go through), but it's still only an attack dealing an average 20 damage for 2 energy. And then its second attack: it deals the same average damage as White Kyurem's second attack, only instead of a coin deciding it's 20 less or 20 more (80 or 120, instead of flat-out 100), you need to discard an energy, which is worse. So, definitely underwhelming as well. Even worse.