Blackwing Corruptor is amazing and has been a consistent meta presence ever since whoever it was came up with Malylock, even if Malylock has fallen off quite a bit in the last few weeks. Patron is actually pretty shitty without Warsong, so I'm not sure how to rate it, but obviously it's a big deal along with Emperor. Nefarian is played in a handful of decks, and some dragon decks also run Blackwing Technician.
Also Quick Shot, Flamewaker, Imp Gang Boss, and Revenge. So that's 9 cards with at least some notable meta presence, not counting the objectively powerful cards that don't have a meta presence atm like Fireguard Destroyer, Lava Shock, Gang Up, a Dragon Consort. I even occasionally run into Demonwrath when I'm laddering up. So ignoring Demonwrath, that's 13 powerful cards in a 31 card set, 9 of which are used in the current meta.
BRM was plenty strong, but if they want to avoid power creep, each set will necessarily have less and less impact on the metagame because you're dropping the same number of cards into an ever increasing card pool. Unless they come up with some kind of set rotation, which I guarantee would not go over well.