No one is going to argue that instances, whether regular or heroic, are much more difficult to heal. Spells putting less of a dent in a player's overall health pool, having to watch your mana bar, these things make healing challenging. It also doesn't help that many players, healers and tanks included, are still in a Wrath state of mind which makes learning mechanics all the more difficult.
So to all of you on the forums who are begging Blizzard to increase your healing, I want to you to stop and really ask yourself: Is this the role for me. Because it has changed since Wrath. A random queue for heroics is no longer where you go when you have a little bit of downtime. All of a sudden healing requires a great deal of thought, both in and out of combat.
But more than this. We are, in short, the role without a scapegoat. If a tank or a dps fails in something, they can easily shift the blame to a healer. But if a healer fails, he or she will find it very difficult to successfully explain to the group how that last wipe wasn't their fault. Unfair? Perhaps. But that's where we are.
So ask yourself. Do I want to do this? It's not a sign of weakness to say no. It's not a sign of strength to say yes. It's just a personal preference. Can I be the outlet for the hatred and anger that is occurring as a result of the increased difficulty? Do I want to really spend the time to theorycraft all these changes about my character and understand that, at times, I'm going to lose a dps, or the tank is going to die?
And if the answer to either of those questions is no, then maybe you shouldn't be on the forums. Maybe you should be online and paying some gold to your trainer to reset your talents. Healing isn't for everyone. Neither is tanking, nor dps-ing. And if you don't like the changes to one of those roles, chances are you will like the changes for another.
Food for thought.