Reading a lot of nonsense here, mainly about elemental being bad at single target dps.
My main character is a Shaman since always. I can agree that elemental is indeed absolutely bad when low geared on some bosses (like Nazgrim) on which there is a huge skill cap for optimal dps (people that say otherwise, are the ones doing the shit dps), as mistakes hurt our dps bad. This however changes a bit on higher gear levels.
I still have no luck with the trinket from shamans, and I kill them on every lockout. I'm currently using the Black Blood of Y'Shaarj, which is actually a pretty good trinket, and is miles better on AoE fights than the trinket from Malkorok, which is an absolute shit and worthless on trash even.
Regardless, from my experience shamans are more than average on Single Target dps, and not rarely top on meters for any other fight. AoE is extremely high and single target is no less than any other class/spec, and sometimes more with equally geared players.
I'm not going to dig for any stats or charts, but this is what I see and this is my opinion.
Cheers!