The content so far has not been challenging...sadly the days of challenging content is all but gone. WoW has ruined the genre, and SE has already said they are not aiming at hardcore raider. Heroic progression in WoW still offers some of the thrill of getting a boss down first.

Turn 4 is really the only fight that can be considered "challenging" so far, but with some 90 gear, the fight is pretty trivial. I log on once a week for 40 minutes to do coil, and then cap myth sometime later in the week. It's going to be a long time before any more progression raiding comes out since CT will be easier than coil. This mistake is going to be pretty detrimental.