HearthPwn with all the information:
Mobile achievements sighted in an upcoming Blackrock Mountain Patch
We should be close to the phone version release!
Blackrock Mountain full card reveal
Overall, other than the obvious support for dragons, I think there are quite a few situational cards this time round that depends on other cards/conditions to get better value. There are also a lot of cards similar to Bolvar Fordragon's effect which proved to be quite feasible in matches unlike what a lot of people was thinking during the card's preview. However, we need to evaluate the usefulness of these cards as a standalone without the "bonus" effects first. Bolvar was a basic 1/7 minion for a mana cost of 5 which is reasonable.
On the other hand, Mage's new Dragon's Breath spell is a basic 4 damage spell for a mana cost of 5 while Solemn Vigil is a 5 mana cost card to draw 2 cards which aren't very good. Therefore, the good ones IMO are those that are already reasonable for the initial effect like Revenge. (Warrior seem to be constantly getting at least one good control card with each new card addition) It looks like it will most likely be included into Warrior control decks for me. Quick Shot is 2 mana cost for 3 damage and that is pretty good value in itself so I think Face Hunter decks will most probably run it.
It'll be interesting to see which cards make it into the current decks as we only have 30 slots. I personally don't think there will be a lot of dragon decks coming out after this expansion unlike Naxxramas' Deathrattle and Goblins and Gnomes' mechs. The only notable ones I see are Hungry Dragon, a neutral card and Twilight Whelp, a priest card.