I wanted to address a few complaints that a lot of people are making about the current healing model. My goal is to hopefully change the minds of those who think this system has nothing fun to offer as well as to show Blizzard that the changes they've made weren't a mistake. I'm not making any claims that all the healers are equally balanced, or that all the spells are working perfectly, just that things feel pretty good from my perspective as a druid. Now for the complaints:

Healing is boring because there is no decision making. All I do is spam nourish and keep lifebloom up.
This is a gross exaggeration in my opinion. If you can survive heroics doing just these 2 spells, I'd like to see the video. The truth is you're using those spells quite a bit more than the others, but that's not a bad thing. I'm sure it's intended that we use our efficient spell the majority of the time, but at some point that weak efficient heal doesn't cut it and that's when the decision making comes in. So, if you're truly getting by using just those 2 spells, please show some proof.
My heals are too weak.
Of all the complaints this one could be the most valid in my opinion. That being said, I don't think we need a buff, but if some of our hots healed for a bit more I'm not sure it would break us either. The thing is, damage isn't so out of control that we need to be able to put hots on everyone while spam healing the tank to keep everyone alive. If we ever reach that point, I'm sure Blizzard will fix things. What matters is that we can keep up with the damage output and that all our spells are helping us do so - not whether or not our big heal can heal someone's entire life bar to full in 1 cast.
I can't carry the group. I don't want my success or failure based on others.
Admittedly, one of the things that has always attracted me to healing is the control over whether or not my group lives or dies. I liked the idea that as long as I was good at my job, we would likely succeed. Obviously we never had full control with heals alone, but a good healer could make up for someone's mistake with a quick heal or dispel. This is still the case, we're still removing raid-wiping debuffs, landing life saving heals and that sort of thing. Sure it's possible that other players might cause us to run out of mana by taking lots of unnecessary damage(or it could even by our fault), but requiring a little bit of competency from everyone isn't the worst thing to happen to this game...it's probably something that should have happened a long time ago.
I keep going OOM! This is not hard nor is it fun!
I've saved the best for last. This is the number 1 complaint here and it's actually what makes these changes so awesome. The threat of going out of mana is something that makes healing exciting. There have been multiple heroic boss fights where the boss is sub 20% and everyone is low on health and I'm out of mana or close to it. The struggle to keep people alive while trying to hold on to the last bit of remaining mana is FUN and exciting! I'm usually trying to hold out for Innervate to be off cooldown or for the boss to be killed in time. If I use tranquility to bring everyone back up, I've bought myself some time but I'm back to being OOM and have to rely on regen or a clearcasting proc...you get the point. It's kind of like when a raid boss is at 1-2% and people are rapidly dropping, there's a chance you'll get the kill but you're not sure. Those moments are exciting and to have them in a 5 man is pretty cool.