Learning how to do these new instances with leveling gear is certainly a trial and an eye opener.
I mean, I knew things were going to be different in Cata and I am doing my best to adjust. First realization that something needed to change was in Vortex Pinnacle. I am going to reiterate some things Kae mentions that I learned the hard way.
This has been a lifesaver on mana. Roll Lifebloom on the tank and use the Clearcasts to bring up the dps. I am not doing heroics yet, but so far this strategy is working well for normals.
This may be difficult to spec for, forcing you to sacrifice resto talents to go this deep into balance. If you can manage it, great. However, if you follow EJ's post like I did, you may have to give up good 5 man talents like NS and Blessing of the Grove. It's one of those "your mileage may vary" situations, I think. I miss NS for saving tanks and may readjust my spec again when I am ready for heroics.
I am not the running around healer like I used to be. I use Nourish A LOT more on the tank now and while I am learning these fights, it can be rough to prioritize my healing. More than once, I have had to sacrifice a dps in order to save the tank (almost always due to overagro). In addition, I started to get a zen mentality for trash while I was adjusting to the mana changes. If folks were above 50 percent, I wasn't going to fret. All of this is with the mind set that Heroics are going to be different altogether, but whatever I can do to keep me sane while I learn everything all over again is what I have to do.
Couple of my friends pugged Vortex and had a level 81 priest healer. She rocked it and had hardly any trouble at all, on the heels (oh my, no pun intended) of my miserable showing of the same zone earlier that day. I felt dejected and at the same time scrambled to figure out what I was doing wrong. Halls of Origination also made me feel like a crap healer until we utilized proper CC. All in all, Wrath made me feel like a goddess among healers and Cata has knocked me off my pillar. It is a team effort now, so don't be afraid to ask for CC or the tank to adjust how he/she pulls.
Of course, I am harder on myself than others are to me. More than once I heard myself described as an awesome healer. I love you, too, guildies.
Gear choices and measurement
GuildOx has updated gear. I used the Resto Template and adjusted the weights on Haste, Int and Spirit along with other stats. Make use of the armory feature so you can see where your gear stacks up with the items suggested.
Wowheroes and BeImba are still being updated for Cata.
Gearscore always was and will be a spawn of evil. I hope you aren't using it.