Why not both?
My spec is
http://db.vanillagaming.org/?talent#hEozx0hoZxVfzV0uxMy reason for going elemental devestation instead of eye of the storm is that: 1. sometimes you don't get crit and you get push back for days. 2. I am a cow so I war stomp for one free heal. I ran eye of the storm before and honestly sometimes it can be really helpful but most of the time if you play well you shouldnt need more than one heal.
Now shamans are hybrids. You can go glass cannon stormstrike spec if you want, but if WF doesn't proc then you hit for nothing and your spells hit for not much. With this spec and 85 spell power and 4% spell crit my earth shocks can go 12 - 1400 unbuffed. Now take that with a nice windfury proc and you have one shot leather / cloth classes. You can also do a lot of damage with chain lightning, if you get rooted and can't get out you can cast CL / LB and get big crits and then continue to melee once you reach them.
Also, always have a shield / 1h (i use mindfang for now) and you can wreck warriors / rogues because you can get so much armor and your spells hit hard + flurry on a dagger can get you a lot of WF procs.
Also enchant your weapon with spell power. Crusader barely ever procs in the time of a pvp battle with no instant cast melee attacks.
And lightning shield does quite good damage and you should always have it up vs a warrior or rogue