Originally Posted by
Amana
It really depends on what you like to play.
Personally, I rolled as a shaman to heal, and became an elem-speced. Don't get me wrong: I love healing as a shaman (yet I prefer my priest for that, but well, whatever).
Resto shamans are very polyvalent healers: Chain Heal is the godly jesus-beam, and must be (that's my opinion) the best healing spell in the entire game. Though as it's very powerful you rely a lot on it.
But you have other very useful spells. Earth Shield is awesome, especially on paladins (neat, 12k crit heal), HW get more and more interesting as you get stuff, and LHW is your mandatory flash to get someone up fast. Riptide is a nice instant, yet I use it mostly for the instant heal it gives, not the HoT much.
More importantly, it's the gameplay that is interesting: after each Chain Heal or Riptide, you get Tidal Waves which gives more crit on LHW or hastes HW. This is great for 5 or 10 men raids as you have to switch a lot between all your spells. In 25 men raids, you're probably using Chain Heal a lot more.
The downside of the resto shaman is to not have an awesome button for crappy moments: with the exception of nature's swiftness for one instant cast, you spam chain heal in 25-men content for healing the raid, and you still spam chain heal if you have to bring back a lot of people up. No divine hymn, no tranquility (that will change at cata, as we get healing rain). Yet, it's a very efficient healer, as chain heal is a very efficient healing tool.
Give it a try, test for yourself and see if you like it.