Whats up MMOwned. Been absent from the site for a long time now, so now i'm coming back in hope to getting some more reputation here.
I figured this out today when I was respecing to Ele pvp.
What you do is spec enhancement and pick up Elemental Weapons and Dual Wield.
After that you put flametounge on both weapons. Next is respec to Ele and when you do you'll keep both 1H weapons on with the increased talented spell power from Flametounge.
Do your ele spec and spec into Elemental Weapons again. After this you should see that your spell power doubled from what you had with both flametounge before.
Next equiped your real ele weapon and shield and gain the spell power from there also.
So now you have a doubled spell power hidden offhand and the one on your current main hand. My normal Spell Power as PvP ele is 1677. When I did this it was at 2359.
After this go into arena and rape shit =P (ALSO WORKS FOR RESTO!)
Have fun!