I've been having this doubt for a while aswell, what to do when the shammies hit 70.
Gear 'm or level the druid team.

Now that I got them to 70 first thing I'll get is my epic flyers,
then grind rep to get 5 dragons,
in the meantime try some heroics and such and by the end of the year i'll probably still haven't touched my druid team.

As long as you're having fun, the time isn't "wasted"

And what's a better way to waste time,
Sit on the couch watching as the world turns or whatever crap the tv is showing; or
actually have fun.