well it is fun tanking non heroics at times, makes me want to collect the Ele shaman S1 gear for the new 4 set bonus =P
But ya, if you have good gear with enough stam holding aggro and keeping you up is not bad at all in non heroics, having a pally present for concentration aura helps too.
if I ever got enough PvP gear I always thought about a spec to goof around in and tank non heroics, here is what I came up with:
http://www.worldofwarcraft.com/info/classes/shaman/talents.html?5503015500001505100005050001550013000000000000000000000000000
this gives you some of the burst of a ele shaman with the ability to negate some more dmg using enh talents.
the enh talents also help decrease mana usage on shock spells, while I wouldnt melee crit often at all when I do my next shock is cheap, and I also will attack faster which aint half bad when your using FT, and I even get parry, even tho this reduces some of my threat regen i rationalize it like this, I wont get much threat from my melee strikes anyhow and this does not affect any other damage i would do including flame tongue procs.