I know, the baron is the easiest fight in WoW, far easier than Hogger, and if you have any trouble with him when there are more than two guys in your party you're some kind of a loser.
Still, I have trouble with this fight as a healer. On my lvl 60 holy/disc priest (5/8 devout and various other blues) I find it pretty nerve wracking, and I just tried it for the first time on my druid, lvl 57 resto specced. I joined the group (all 60s, mage/warrior/shammy/lock) because they were desperate for a healer and I warned them that I might not be able to pull it off. Still, I surprised myself with how badly it went. Sure my druid is only 57, but with arcane Int he had 5400 mana, plus innervate, plus a superior healing potion, and 30 points in Resto. For all that I went OOM well before the baron died and I didn't even have enough mana to combat res the tank.
The combination of hard hitting, mortal strike, and slow heals on the druid makes it especially nerve wracking for me. I don't like the idea of healing through mortal strike since it's a big waste of mana, but when the tank is at 25% health I don't dare wait until the debuff goes away. Also, everyone else in the party was taking a lot of damage. I think the shammy was probably getting shadow damage aura, and I suppose the mage was getting beaten on by the skeletons. I burned some mana tossing big heals to those guys, which in retrospect may have been a mistake. Maybe I just should have given them HoTs but the mage got dangerously low at one point. Is there some conventional wisdom on how much mana the healer can expend on the non-tank party members? I assume I at least have to try to keep the mage alive too. At least on my priest I can shield him while he nukes the skeletons, but on my druid that wasn't an option. Lack of Shadow Protection spell wasn't exactly helping either.
It feels very retro talking about the Baron fight as though it's still a challenge, but for me, retard that I am, it is. (Except when I'm tanking it. It's an extremely simple fight from a tank's POV.)
My druid has almost no mana-per-5 and relatively low spirit too. His in-combat mana regen is pretty sad compared to my priest, who at least has lots of spirit and all the disc talents for regenerating mana during a fight. I had thought the presence of innervate would compensate for that at least in part, but it didn't seem to.
Anyway, any thoughts from experienced healers would be appreciated. Despite being very close to having my second lvl 60 healer, I feel pretty clueless in that area of the game.
Note: all of this assumes non-leet gear. I'm sure the math works out a lot better if you have Tier 1/Tier 2 etc.