Vaneras has an update for folks on the Mount Hyjal instance, specifically regarding Thrall and Jaina and their survivability in the instance. According to Vaneras, a hotfix has been deployed that'll increase the pair's hitpoints, making them just a little harder to kill, though we doubt it makes the instance any easier.

Here's a brief timeline for those folks who are probably wondering why the Thrall and Jaina are getting a hotfix. In late May, they instituted changes that would weaken Thrall and Jaina in terms of attack power and hitpoints. In early June, however, they also managed to buff Archimonde, allowing him to deal more damage... which is problematic, given that you're also taking Thrall and Jaina along through the entire fight.

The change should make the whole instance a bit more manageable, though priests, paladins, and shamans will still have to watch the hitpoints of the raid and of the NPC duo.