I have been thinking about this a bit too. Initially, with my Paladin + 4x shaman team, I was thinking about having it so that the shaman could all dual-spec elemental/enhancement (except for one that would be elemental/resto) just in case there were any fights where melee were better than ranged. (Un?)fortunately, I haven't run into any situations where melee would make short work of something but ranged would have difficulty, so I never tried it.

I will be making an all Worgen, all Druid team - though I'm not sure if my DPS will be feral or if they'll be balance - or maybe dual spec to try both.