Priest is weak right now but if it gets any good spells to discover next expansion, it will be the sooooo annoying. The strategy isn't good yet but I agree with OP that it's whole strategy feels really lame to play against. It can discover copy after copy of board clears and it competes with mage and rogue for the most bullshit cost reduction. Luckily, they currently don't have any good value cards to take advantage of.
I mean, they were bad before rotation too and were still bottom 3 so unless Blizzard prints another Mass Rez they still aren't going to be that strong