Id say it all depends really on what you want to do mostly, act as MT, OT or support tank (we have used that sometimes when we try new encounters).
The 0-49-12 is the cookie cutter and probably the best MT build around. I found one problem though.
As my avoidance got better and better, since I focused alot on it rather then just going all out on stamina, I noticed I took less and less damage (shocking isnt it?

). Hence my mana regen became an issue.
As of this, I tried out a new specc: 0-38-23
http://www.wowhead.com/?talent=qZVhtIx0dMMqZVbxt0bzb
The reason behind this was to get the sanctity aura and use that while MTing and the retribution aura for everything else. The Seal of Command is more or less a filler and fun to use while just alternating on stuff.
I tried this out yesterday in Gruul and it did work nicely, although I did miss my reckoning, one handed weapon and avengers shield. But I did find that those extra 10% (+2) really did help alot in building hate fast.
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