This is how I boost.

I am s2 pvp geared on my enhancement shaman and leveling four elemental shaman.

I must say, my level 70 shaman can solo ramparts without heals though. (Still needs some minor kiting ofcourse.) With the elemental shamans it's just, so easy..

I -know- I can handle tanking at least up to mana tombs. I two manned mana tombs once with a healer. And I do about 1200 dps on slightly lower level mobs, so with dps there's no probs as well.

So, for boosting upto 70, it's definatly doable with an enhancement shaman. Fury warrior has slightly better aggro abilities, but the focused dps of enhancement. (dropping mob by mob quickly) Is really good too. I usually don't have to start healing before I already killed two mobs. So aggro isn't much of a problem.

I must say tho, this is with a pvp geared enhancement shaman. 1.2k Hp, 400 resi, blacksmith hammer 2nd upgrade in mainhand and s2 offhand 2.6 speed axe.

Here's a small movie of me and my alts in ramparts for example. http://www.wegame.com/watch/Multibox...fire_Ramparts/

And if you mean boosting with lower level chars. Don't try to tank with a level 61 enhancement shaman, really. xD Just not sure what you mean exactly.