On a hunch last night, I went through all the arms and armor I had stocked up for the future (gifts Grimm, etc.). As I feared, what I found was that at least half my gear had lost its value due to stat creep.
Here's what happened: at the 3.0 patch, a new stats system kicked in. +Heal became +Spell Power, +Spell Hit became +Hit, and so on. In the process, the equations all drifted a bit, and some gear that I had no longer had the stats I needed.
For example, a chest piece that was a complete upgrade for me turned into one that had no health boost, and was in fact a downgrade for me in that regard.
Yarley checked hers out too and found a few (but fortunately, not as many) items as well.
So ... check your bags and make sure all the stuff you were hanging on to is still worth hanging on to.