The big news in the tanking community is that Blizzard is re-introducing Sunwell Radiance for Patch 3.3. Chill of the Throne will reduce Dodge by 20% everywhere in Icecrown Citadel. I thought I'd take this opportunity to put down a few general thoughts on Avoidance.
In my view, when Avoidance hits 50%+, healing gets weird. Basically, the next attack is more likely to miss than actually connect. So it becomes very hard to predict how damage will be dealt, which is the essence of good healing. You start healing very generally, aiming at the worst case scenarios. The tank's actual health doesn't really matter anymore.
And for harder content, the damage per hit is very high to actually threaten the tank. So you end up with the scenario where the next attack is probably going to miss, but if it does hit, it will do over 50% of the tank's health.
Healing is much more fun when tank Avoidance is much lower. When you can accurately predict the pattern of damage and adjust your healing to match.
But tanks in WoW have very high Avoidance rates. That 50% magic number, where an attack connecting flips from being likely to being unlikely, occurred in Naxxramas. The very first tier of raid content.
In my opinion, WoW would benefit from a much more radical solution: don't put Avoidance on gear. Tanks would have their base 10-15% avoidance, plus another 10% or so from talents. That would give a tank-specced character about 25% avoidance, which is a pretty good number. Attacks would be likely to connect, but a miss streak here and there makes things interesting.
However, tanks would need more stats dedicated to them. They would only have Stamina, Expertise, and DPS stats. Perhaps something like bonus healing done to them, or a resilience variant, or bonus threat. I'm sure there are many possibilities.
But Avoidance has to be reigned in, and I think the optimal Avoidance value for fun gameplay is about 25%, which--after base and talents--doesn't leave any room for avoidance on gear.
Edit: Honor's Code goes hardcore and proposes eliminating tank gear altogether!