The only spell power and intelligence mail in Vanilla came from Molten Core and Blackwing lair, or if you were lucky enough to find a leather worker who had the blue dragonscale recipes. So if you did decide to be elemental you'd be prancing with 4k mana while the priests and mages in the same level gear had 6k, so if you were serious about elemental you had to wear cloth.
But lets not mince words here, if you did attend a raid as a shaman in vanilla the only button you'd be pressing for the entire time was lesser healing wave or you'd be /guildkicked same for anyone else who had a heal button regardless of spec or equipment. Vanilla was complete fail and I'm glad that it's gone.