I've been thinking a bit about the proposed avoidance nerf, and how it will affect fresh 80 tanks as well as end game tanks. I also wonder if it is enough - one of our U25 geared pallies on the PTR reports an avoidance drop (before DR) of around 1%. The post-DR figure will be even lower (ie a bigger nerf) because more the the pre-DR avoidance is now parry, which diminishes faster. Still though, that's not a lot.
If Blizzard changed the way DRs are calculated then total net avoidance for well geared tanks could be reduced without harming levelling and lower geared tanks. There would be no need to change ratings, and no outcry over the changes from the community since it would require a lot of testing for the actual effect of the changes to become apparent.
I also wonder whether it is now time to stop defence skill increasing the mob's chance to miss you. It seems something of an anachronism, and I wonder whether druids are adequately compensated for lacking this non-diminishing avoidance stat.