WotLK beta changes are being released fast and furiously. There are rumors of a November release, but my money would be on December-January (Just my personal opinion!).
I wanted to put out another quick note that information from the WotLK beta is being rendered inaccurate almost as fast as it is being posted. Things are being updated fast, fast, fast! I made a post about talents a week ago, and the talent builds I linked on Wowhead are already messed up from the talent calculators being updated (points in the wrong talents, not all talent points spent, etc.). Just keep that in mind when browsing the web: many linked WotLK talent builds are going to be inaccurate now (unless updated).
There hasn’t been as many priest changes as some of the other classes, but there was a good amount in the most recent patch, most notably the removal of the cooldown of Circle of Healing (and about a 25% increase in mana cost).
Korra (a WoW class designer) said (on the WotLK forums) with regards to the CoH changes:
We’ll be removing the imposed cooldown on Circle of Healing in an upcoming beta build. We’ll experiment with the ability having no cooldown, but it’s still possible we may decide it needs it. We are indeed concerned with the impact AOE heals such as Circle of Healing, Chain Heal etc. have in endgame raiding, but we haven’t decided the best way to address the issue.
This change to CoH is huge, but nothing to set your heart on. There is still a lot of balancing that needs to be done between all the healing classes in terms of healing ability and I’m sure we’ll see many more changes soon.
Another interesting thing is that in the most recent patch, Blizzard started rolling out some of the Inscription glyphs. Nothing has shown up for priest spells yet (soon, hopefully!). Mages will be able to Polymorph: Penguin. How sweet is that?
The best place for the most recent WotLK news and updates is the MMO Champion News page. Keep an eye on that to stay in the loop if you are not in the Beta.