In Batlegrounds ele shaman is one of the best classes to play, cuz u are a ranged class and u can run in wolf and heal if u need. Although if u are in trouble u can trow people away or u can place grounding totem to prevent some Death Grips from DK's for example.
In wpvp is almost the same...ele shamans are good only cuz u can run and hide and attack again and heal and hide that's the strengh of that class so in wpvp u will find alot of pilars and alot of place to run :).
Enhancement for me it's a little bit boring, but it's also a good spec. The problem that I find in this spec is, If u can't do damage on the enemy for example vs a warrior u know that soon or later u will die cuz u dont have marge to do more damage than u do...u don't have burst only with wolfs. I notice this vs paladins, warriors and Dk's mostly. (Note: I don't have the experince that I have on Elemental)