It's a cross of personal preference and what you intend to do most often. If you're not going to be with a reliable group/healer, Elemental Devastation + Glyph of Shamanistic Rage are likely better for you. If you will be around a decent group/healer most of the time, the extra damage from Static Shock + Glyph of Lightning Shield will probably boost your damage a little.
Long version :
It's hard to say, since PvP is so inconsistent and you can't just "sim" it. Overall I suppose it could be seen as a choice of personal preference.
Elemental Devastation procs substantially less in PvP than it does in PvE, since we frequently use our Maelstrom Weapon proc to heal or CC rather than cast Lightning Bolts and frequently use Frost Shock in place of Earth Shock. If you intend to focus primarily on arenas, where you're constantly under pressure and don't usually get to attack with your Maelstrom Weapon procs, this talent probably starts falling behind (I say probably because I am going by logic, not science).
Static Shock is a lesser gain, but arguably a more reliable one so long as your Lightning Shield is up. Clearly you need to be using the Lightning Shield glyph to make this efficient, and that does come with the added benefit of getting the damage from Lightning Shield itself all the time as well. As I mentioned above, if you intend to go heavy on arenas, Elemental Devastation will likely fall behind in damage, as its primary source of procs won't be used as often, and the Static Shock setup will likely allow you to do more damage. If you intend to do mostly Battlegrounds, then it's a slightly harder call. You would likely be able to keep Elemental Devastation up a decent amount since you're not likely to be pressured into healing/CCing constantly, so the extra crit may prove more useful than small, occasional extra hits.
That was going purely by damage though, and the other factor here is the glyph you may want to replace the Lightning Shield glyph with, Shamanistic Rage. The ability to cleanse yourself of all magic debuffs is definitely a tempting one, particularly if you are not going to be regularly grouped with other reliable players, particularly healers. If you intend to go into arenas, or even BGs, without a reliable healer, removing magic debuffs yourself (All of them at once even!) is phenomenal, and it may be worth taking the slightly lesser overall damage from Elemental Devastation to get it, but that really comes down to personal preference.
There is also the option of maxing Toughness and dropping the last point in Elemental Devastation to gain the nice snare reduction (not that we aren't well equipped for that to begin with) and extra stamina, as well as taking the Shamanistic Rage glyph. This would mostly be if you were having trouble surviving though, the others are clearly better for damage purposes.
thank you so much anodyne... that was an incredible response.
I always hear how little defense enhance has, but tbh it does have shamanistic rage. It is so hard to call because dispelling dots ALWAYS gives bonuses to compensate... haste for ele, runes for dk, UA damage, aoe fear off DRs for spriest...
But I think I will go with the lightning shield after what you said...
I like being able to throw chain heals sometimes, but really the clincher is refreshing LS is a waste of a GCD constantly. This shield will hurt rogues and warriors the most...