Originally Posted by Chicken

There's definitely situations I can see that build being powerful. I'm pretty sure that if you don't need to aggro up to three adds solidly at any point in your tanking career, you'll be getting more threat out of Sanctity Aura; and that for a lower mana cost as well. For raiding in particular Avenger's Shield isn't really needed outside of a very few fights in-game; I'd hate to be without it for tanking at Shade of Akama for example, though I'm certain I could manage without with some effort.

The downside really is in the fact that you lose Ardent Defender and Reckoning; Ardent Defender is most likely not worth speccing for if you can only put 2 points in it. I was thinking in this direction myself: Talent Calculator - World of Warcraft (If you take out the points in Ret, get Avenger's Shield, and put the 'basic 20' in Holy you'll get the build I'm probably taking next patch)

From a pure threat point of view in any situation this build is going to be pretty strong. It'll actually sport ~19% more damage (and thus threat) on practically everything you'll face while raiding. I'd say it's also got good survivability in a single hard-hitting target situation. It'll be less good than a build with Ardent Defender at taking damage in a situation with a lot of smaller faster attacks though, and it also lacks Reckoning which is a nice threat boost in a situation in which you're tanking a lot of mobs and are also expected to outaggro single target DPS on a specific mob.