Rogues are no worse than warriors and spriests on PTR. Definitely not over the top.
Monks however.. oh god.. I don't know much about the class, but I saw one of the currently highest rated windwalker monks streaming from PTR doing 3v3, and he did like 1.5 million damage and 300k healing in the beginning of the match, when the 3 other damage dealers were strugling around 300-400k damage done each.
Basically huge sustained and unpeelable damage, with the ability to shut down an enemy team completely with ring of peace.