My elementals are easily able to pull down 12-14K in mostly PVP gear on the raid boss target dummy. If I chainlightning spam I can get 20-22K on the 3 raid boss training dummies in Ogrimmar. I have reforged for some +hit so my crit and haste have dropped off but. I can burst at 20-28K single target for about 20 seconds.

But that being said I macro use of trinkets, racials and elemental mastery into my rotations 2-step macros. Sub-par DPS could be a macro issue. I think on my girls I even mix in the occassional purge and windshear on my shammies so I could probably do better if I would refine it a bit more.