1. WTF is my disc priest on the dps meters?
Blizz, in their infinite wisdom, gave disc a few new tools. Among these new tools are Atonement, Evangelism, and Archangel. Atonement heals people when we smite, and damaging stuff gives us levels in Evangelism. We can use these Evangelism levels with Archangel, which gives us mana and increases our healing power for 18 secs. So your priest is smiting to heal people, make their heals more powerful, and get mana back.
2. What role is the disc priest suited for?
A disc priest still has the shields of awesome we have come to know and love. Our tank healing is still quite strong as well, and our group heals not quite so strong. In a 10 man, I'd bring a disc priest in as a tank healer, or as a supplementary healer. Personally, I act as a supplementary healer with a holy pally and a resto shaman. My strong tank heals help keep the tanks up (and wow, do tanks get hurt more now), and my bubbles help prevent damage. I've also got that frisbee of healing goodness bouncing around the raid, and in a pinch I can group heal.
3. Why should I bring a disc priest to raids instead of a shadow priest if they're going to be dpsing anyway?
Well, a disc priest is not going to be dpsing all the time. It's an occasional thing. Also, while a shadow priest does do much more dps, their healing is dumb. A disc priest can smite, turn around and save that mage standing in the bad stuff with penance, throw a few flash heals on people who are getting low, then smite again. Yes, the disc priest is not going to be high on the dps meters, nor should we be. We heal, with a side order of dps when possible. A shadowpriest hurts, with a side order of unintelligent healing.
4. Should disc priests be able to roll main spec on gear with to hit on it?
Honestly, I'm torn on this one. Yes, to hit now has some value for disc priests, but I think it has much more value for the dps casters, and given the amount of competition for cloth, I'd say no. Even if I do want those stupid bracers that drop every week and every week a dps gets them. Grr...
5. Why did my priest suddenly sprout wings?
We drink too much Red Bull now.
Seriously, your priest has wings because they popped Archangel, which increases healing power and mana regen for 18 seconds. The wings are just a lovely side effect.
6. What's that big golden dome thing?
Power Word: Barrier. It's your friend and a group shield. Stand in the dome, please.
7. How has disc healing changed since this new patch?
Well, it depends on the priest. It is currently possible to heal as we've been doing, but given the changes to our class and Blizz's stated intent, many of us are trying this new smite-heal thing. We still bubble, we still penance, we just smite stuff and pop wings occasionally. Think of it like a holy pally dpsing to get haste or mana or whatever the heck they get when they dps. For well-geared priests, PW:S, Penance, and Flash Heal are still the winners, with Prayer of Mending (whee frisbee!) and the occasional Renew making an appearance. Less well-geared priests may have switched to Heal. And, of course, everyone tends to heal slightly differently, so one disc priest may Renew every chance they get, and another may Penance, and a third may flash heal.
8. How can I help my priest come to terms with these changes?
Normally I'd suggest running older content, but since I saw two ICC-geared tanks get two-shotted in Ulduar this week, older content might not be so good. Give your priest time to come to terms with their new healing. Don't immediately throw them into the deep end, and give them the freedom to screw up. Switching back and forth between dpsing and healing's a BIG shift in our thinking and the way we do things, and it's going to take some time to become comfortable with it. Give then that time, and be thankful we're trying to learn this new style now, rather than when Cat hits and you want to get into that shiny new raid content.