Hmmm. Let's see. Off the top of my head:
Immunity to Polymorph/Snare effects.
Crowd Control (Cyclone/Roots/Hibernate)
5% crit buff
Can do dps reasonably well in the same gear/spec, so can dps during phases where no offtank is needed.
That said, I do feel like a prot warrior's toolset is larger, but being a bear does have some advantages. You still get all the abilities you have in Caster form, and I think some bears forget there are often times in most fights where you can pop out and throw up a Tranquility, or help dispel, or CC something, or whatever.
Kathy, I said, "I'm lost" though I knew she was sleeping
I'm empty and aching and I don't know why
Counting the cars on the New Jersey Turnpike
They've all gone to look for America