Edit: As of build 15640, Atonement is no longer a glyph or a talent. It appears to be a baseline ability built into Discipline and will not be accessible to Holy. Discipline Priests will learn it at level 60.
Plan on going Atonement? The process has changed.
For starters, Atonement isn’t something you talent into anymore.
Instead, all the relevant abilities are located in your glyphs (See the above screenshot). Atonement presently takes up a Major glyph slot. For it to continue being a strong style of healing for Priests, you’ll need to grab Glyph of Smite. You could grab Glyph of Holy Fire but it doesn’t seem to be as important. In order to be an Atonement priest, you must have the Atonement glyph and the Smite glyph. The Holy Fire glyph makes the spell instant but might not be a necessity depending on the encounters.
Not quite sure how I feel about moving Atonement from talents to glyphs. I understand what the move was made: So that Priests could really pick out their talents without feeling they had to force themselves down one route. At the same time though, limiting it to a glyph means that Atonement Priests don’t have as much flexibility either when it comes to glyph selection. I’d wager that you’d still have to grab Archangel in order to remain competitive.
The bright side is that you can go Atonement as Holy. Chakra: Chastise increases the potency even further.
That third glyph slot?
There hasn’t been much change to the style of healing. If you’re comfortable playing Atonement right now, you should have no difficulties heading into the expansion. At least you can set up a specific glyph page just for Atonement.
Leveling as Smite spec? Still good to go (I’ve been doing it from 85 – 87).
Will you be giving Atonement a shot in Mists?