Over on the official forums, Tseric posted some fairly major hotfixes that went live last night/today.

Tuesday:

Grull should now correctly use his hurtful strike ability.

Nightbane's melee damage has been reduced.

Nightbane's breath attack and rain of bones now target those players attempting to avoid his attacks.

The Romulo and Julianne encounter has been retuned to be less difficult.

Hydross the Unstable no longer deals a crushing blow.

Warbringer O'mrogg's status will now reset, after a wipe during his enraged state.