This was actually an offhand remark of Ghostcrawler's a few days ago, but it didn't seem to get much attention. In a thread devoted to the possibility of extending buffs like Blessing of Kings to additional classes in Cataclysm, Ghostcrawler mentioned the following:
I think there's a cogent point there about the extent to which raid mechanics have to reflect the current state of raid buffs and cooldowns (and vice versa, I guess), and there are a few additional clues as to Blizzard's thought process on Cataclysm encounters. Right now it's so damn easy for players to die to massive raid damage or even targeted abilities (e.g., heroic Blood Princes, heroic Lana'thel, Harvest Soul and Spirit Burst on the Lich King) that Rebirthing a fallen player is pretty routine. A 10-minute cooldown on battle resurrection has also made the limited attempts mechanic in Icecrown more bearable.
Then again, on truly difficult encounters, a 30-minute cooldown is still going to be one ugly mother. It wasn't all that long ago that my raid seriously debated whether to wait between Kael'thas attempts for our warriors' Shield Wall cooldowns to come up (30 minutes!), and the idea of doing the Cataclysm equivalents of Yogg+0 or ToGC-25 Anub'arak with only two battle rezzes an hour per druid is enough to give me hives.
It's another blow for druids, who are already reeling from the probable loss of Tree of Life form, but I guess we'll see how it plays out on the beta. If the need to heal raid damage requires less in the way of hair-trigger reflexes, then we really may not notice the increased cooldown as much. However, between things like this and the large-scale retreat of raid and damage buffs, I'm becoming more and more certain that Cataclysm is the closest thing we're going to see to a "classic server" experience.