I'm not sure if everyone has seen this, but sarth 3d 10 man has been tanked by voidwalker. Apparently having 75k hp is useful in this encounter... Anyone care to comment?
Forum post: http://forums.worldofwarcraft.com/thread.html?topicId=14990765757&sid=1
You tube video: http://www.youtube.com/watch?v=-uR4zYa6cvM
I would not expect the Voidwalker to continue to be an excellent tank for challenging raid content.
The health boost was largely for PvP reasons and the damage avoidance was to make up for limitations in pet AI and master control, not to let you opt out of having to manage tons of incoming damage on your main tank. :)