Yes and no. I think SD is broken, but even with out that Arms still does a lot of burst. It's just the way the specs are designed. Arms is burst damage. It's just the way the spec is with long CD/high cost attacks. And then Fury is consistent damage. Other than the extra healing you get with fury, the only real difference is in the way you deal damage.. And in pvp, especially with a melee class, higher burst will almost always be better.
You might think to yourself that well, any spec can use SD and have good burst... but that's not really the case. Execute is quite sad on Fury/Prot glad stance. Like it doesn't even come close to comparing to Arms. I get execute non-crits for an upwards of 80k with no CDs. Fury/Prot is 1/4-1/8th that. There's literally that big of a difference.
Right now on the ptr, it just seems better to be Arms or Glad Stance. I mean, Arms is the best of all 3 specs(imho..especially with SD) but Glad stance seems pretty solid all around. It's play is smooth, has insane survivability, good burst with the new talents, a little bit more mobility potential with that shield charge ability(or w.e it's called).. Oh, and did I mention that it plays smooth. Seriously, Prot feels waaay better than Arms/Fury currently. You can always press something and you don't have to deal with stance requirements. I mean, the only thing you really lose as prot is Rallying Cry. Which sucks.. but hey, at least you won't be a target really.
Also, it's far too early to tell which specs will be good for pvp or not when WoD comes out. They still have a lot of numbers to tune.