Bah, I had a nicely written reply, and i lost it!
I use the procelain crab, reforged to mastery, and throngus's finger.
I keep two stamina trinkets in my inventory for those fights that need the extra HP boost
I'm planning on picking up the Impatience of Youth once i've got the mount (priorities!!! :P)
I agree that the Darkmoon card seems a little bit lackluster with only 10k hp click. For .2% less dodge I would take the crab over it, as the mastery proc happens quite frequently (don't know the ppm though), or at least seems to happen quite frequently.
As far as armor trinkets go (since the wotlk ones are being adjusted to be in line with the cata ones) I have no idea how they stack up against the others. I remmeber back when I was tanking BC raids, the bears were the ones that wanted the armor trinkets and we tended towards the sta/avoidance onces. Now with a new armor formula, i have no idea if they're any good!
I think i'll end up keeping different ones for different situations, a couple for avoidance, a couple for mitigation, and a couple for pure sta/efective health.