I'm seriously considering respeccing to tank on my Shaman.
It would be pretty damn cool as there's like no other Shaman tanks.
The spec i'm considering would be this: http://db.vanillagaming.org/?talent#hVfzZVic0Exut
I mean, it might actually work at least in 5 man dungeons, and as OT in raids. Rockbiter poundings would be equivalent to a warriors sunder armor... there's no reliable taunt spell per se, it would be earthshock and hope you get aggro. But then again do Paladins actually have a real taunt spell? IIRC they didn't in Vanilla and they can tank fine.
Keeping stoneskin totem up and getting the armor bonus talent and you'll have about as much damage reduction as a plate wearer. Popping improved stoneclaw totem when you lose aggro on more than 1 mob, just to keep it off the clothies (though i'm not sure how effective as that totems taunt is pretty weak, might be better to just spam earth shock)
I'd like to give it a try...