Many hotfixes are going into the game tonight involving raid encounters in The Burning Crusade, especially Gruul and Magtheridon.
Eyonix posted in this thread about the Magtheridon hotfix:
The Magtheridon encounter has been rebalanced to be somewhat easier and should now better keep to proper raid progression.
There is also talk of Gruul's hp being reduced as well as the damage on the Shatter effect being much lower, in addition to the changes mentioned in the previous hotfix news post.
Edit: Rumors of Gruul's hp and Shatter damage also being lowered are confirmed in this thread.