Another point of view.

Beside my mage I have more or less decided that I will level my shaman as my second character, and due to the healing situation in my guild I have been thinking about getting it leveled rather fast.

As you might have guessed I want to play restoration and this is due to several reasons:
1^st Shamans is in my humble opinion the “best overall” healing class and perhaps the one who have been changed the least for the release of Cataclysm.
Chainheals initial healing has been nerfed, but I do actually thing that it is a good change since it will force you to use a larger part of your healing arsenal instead of just spamming Chainheal because it was such a strong heal both for AoE, which it still is, and for single target healing where it would crit for 14-18k and leave a massive hot on your target.

One of the major changes to most of the healing classes is that they now have the opportunity or they must do damage now in order to keep a buff up on themselves. There is those who think that as a healer the only thing you should be able to do is – Heal, and then there is those who adjust and see the opportunities in the changes as for an example I will take restoration shamans since it is the class which I am most familiar with. The talent “Focused Insight” – “After casting any Shock spell, your next heal’s mana cost is reduced by 75% of the cost of the Shock spell, and its healing effectiveness is increased by 30%”. This is a massive “on demand” burst healing one can launch while not feeling guilty of doing damage to the boss with a few GCDs add this 30% effectiveness with our mastery Deep Healing I think that Shamans will have the opportunity to specialize more in either raid healing or tank healing.

In addition restoration shamans gets a new heal “Healing Rain” which in its current state isn’t that healing impressive (from what I’ve read) it heals for close to 2k pr. Tick if there is 5 or less people in the area and then heals for less as more and more people is in the area, but since it is capable of proccing Earth Living on the target it is in my opinion a decent AoE heal. One has to remember that the amount of “burst” both on the tanks and the raid is being reduced and the tank dying within somewhat near of 1 second shouldn’t be that much of an issue anymore.  

Another new talent is “Telluric Currents” which will allow you to cast Lightning Bolts and essentially will allow you to do damage instead of just ideling / throwing a heal which you know will be 70/80% overhealing aswell as the druids hots would heal the target up without your help. And again it is the idea – Healers can do if they please do damage, and this is not a new thing you could take a look at almost every single video released by Paragon or Ensidia; If the healer got mana and a free GCD he or her usually throws a DoT on the target and when you search through some of the wipes you have had on 1-2% imagine if your healers would have had a DoT running almost constantly.
Another aspect is in my opinion that since most guilds most likely will run with 7 healers until they get the hang of the fight, enrage is first a problem when you actually manage to stay alive for that long, you will not be as penalized if the healers can do some damage. I am well aware that they won’t top damage meters or do billions of gazillions of damage, but every single bit of damage counts for a first kill! – Why else would we do theory crafting, respec for encounters and use pots and flasks.