It's hard for me to write about protection right now, because it still doesn't feel finalized to me. I've been tanking on the side lately, since raiding is on hiatus until Mists, and I have mixed feelings about it. The thing is, I don't think it's because the current state of protection is bad, so much as I'm spoiled a bit.
See, here's part of my problem in terms of being fair to patch 5.0.4 for protection. The protection warrior talent specialization was the best designed talent specialization in Wrath of the Lich King, and it was the best designed talent specialization in Cataclysm as well. And it was better in Cataclysm than it was in Wrath. In short, not only was protection the best spec in the game for four years (2008 to 2012) but it managed to be the best spec in the game without being overpowered, in fact being a better spec than specs that were overpowered. You can keep your paladins, your druids and your DK's, all of whom had their moments of being blatantly too good for this fight or that fight. Warriors were never that. The tanking warrior was the best designed spec because it managed to have tools for every single possible potential tanking situation you could imagine without ever once being considered the only possible option for the job.