Reading some the thoughts from Blizz behind Cataclysm it seems that in raids a lot of the limiting factor on fight length will be healer mana as we wont be getting the regeneration we have enjoyed in Wrath (though this has been a bit over the top for most fights if you had replenishment).
This will be coupled with more regular damage to the tanks and raid to be healed through. But they will be removing the spike damage we have seen in wrath where if you are not bomb healing a target at certain points a tank can get almost 2 shotted.
I just wonder if this will make healing less of a challenge for Cataclysm where you will be worried about mana conservation above all and how you eak every last drop out of you toon while the tank take a monotonous pounding. Overhealing will become a big issue again with people watching it like a hawk.
I am asking myself if I will enjoy this way of doing things if it heads this way (though as you know I am tempted to reroll tank for Cata). I am a healing child of the Burning Crusade/ Wrath where overheal was only an issue if you regularly ran out of mana and you like on a knife edge of high raid and tank damage in a lot of fights. While it can be a bit stressful I wonder if the watching my mana bar and being a dispelling monkey route will be as fun?