I’d like to take the time to offer some ideas, highlight some glaring issues, and also point out reality.
Ideas:
First: In lieu of Totemic, if there should be a change to Enhancement so it has the option to tank, then it should be in the Enhancement Talents, not the Hero Talents. This way players 10-70 can fill the role of tank along the way, learning as they level.
This could be done with a few key nodes being made choice nodes, so you can choose either the DPS or the Tanking option.
Alternately, this could be done with the very first node where you select Stormstrike. It could become a choice node, with the player choosing from Stormstrike (in which absolutely nothing changes from the way it is now) or Stormbreaker which would give (just throwing numbers out there, balancing would obviously be different) a 33% damage dealt reduction, +Armor, +threat, Lava Lash becomes Magma Wave, and casts a short wave of magma in a 180 degree arc in front that has extra high threat. Crash lightning makes Stormbreaker hit all enemies in X yards., etc.
Additional Alternate: If we can do this for the melee centric Enhancement, why not do it for Elemental as well? Elemental Shaman would gain a lot of extra survivability, range would get limited to what Dracthyr currently are at, and it would focus more on shocks, totems, and RNG’s for insta-cast chain lightnings.
Glaring issues:
Raid Finder/Group Finder would become REALLY big issues, because a bunch of mouthbreathers would queue as Tank, play as DPS, and wonder why the healer can’t keep them up.
Reality:
For many, many technical reasons there should be a division between tank and dps specs, and it is not likely Blizzard will try to mix the DPS and Tank specs again. They had that originally with Druids. They tested it with a few million Death Knights. They concluded that they wanted them seperate.
Also, enhance is a DW spec, and one of the biggest arguments for Shammy tanking is that we have shields. Well, the shield specs for Shammy are Elemental and Resto, so either there’s a new spec, Elemental becomes the tank spec, or (and honestly as I type this out I realize it’s actually probably the better option from a technical standpoint) Restoration becomes the split spec.
Shammy Tanking should be a 4th spec is the conclusion one should reach about all this.