In the spirit of trying new things, I tanked on the warrior. It was, well, rather nightmarish. Since I didn't know what I was doing, I was pulling rather slowly, so everyone else, including my healer, started pulling for me and then bitched at me when I didn't instantly get the mobs off them. And to add insult to injury, the warlock decided to pet tank about halfway through. We got as far as the harbor (this was Deadmines) before I bailed. I may need to rethink this leveling through dungeons as prot idea. Or get lots of antacids.
I also got to tank heal Patch 25 on Lyllea, which was made much more exciting by the fact that Vuhdo bugged out and my tank wasn't visible. I ended up having to /target "name" and cast all my spells via bartender. It did make a difference in my healing style. Normally I spam flash heal and PW:S, with the occasional penance and a rare greater heal, but since I couldn't easily/quickly identify flash heal on my bars (yes I don't know what the icon looks like) I used PW:S, penance, and greater heal. My overheal was through the roof (since I was always casting a Greater Heal unless Penance was available or PW:S had fallen off, but I had plenty of mana throughout the fight.
My newfound abundance of mana probably indicates that I should stop stacking intellect and start trying to balance it with spellpower and crit/haste. Of course since I have no idea what role I'm likely to have in a raid, it's a bit harder to make gear choices. My guild is currently only doing the weekly raid quest, and maybe, just maybe hitting Ulduar. And I want to do more. I want to see all of Ulduar, not just Flame, Razor, XT, and maybe Kologarn. I don't really care about seeing TOC but I do want to see ICC, and I don't want to pug it. And right now, I honestly think none of that's going to happen with my guild. We've never been hardcore raiders, but it seems like we're just social now. And while I love the people in my guild, I don't know if that's going to work for me. I'm actually pondering trying to get my gear up to ICC levels, then see if I can find a raiding guild that only runs 25 mans (so I could still heal for Silver Dragoons since they only run 10mans). But that'll take a while, and in the meantime, I'm going to go back to leveling alts. Go go shammy and warlock!