Ret's quite simply don't "fit" in any setup for RBGs atm, no aoe controll except a 3sec blind, 30sec CD single target snare, weak survivability. If you went holy on the other hand you'd have one of the strongest heals in addition to being able to stop all crits from enemies which is insane.
For 5.2 rets get dispell on hand of sacrifice so arena is getting a pretty large bandaid, still not potent enough in a 10v10 rbg though.
6 Second blind, and what 30 sec cd single target snare? Also... yes, Holy is strong, but if you are getting Denounces off, that is the other team's fault.
From a Ret to Ret PoV - Yes, it is worth PvP'ing as Ret in 5.2.
If you have a different class, probably should keep it.
Recap~ IF you're already doing some PvP in 5.1... we're much better off in 5.2 than 5.1.
Many small buffs add-up to the nerfs some of our worst offenders got.
Two min wings and 5% more on SoL will be nice for full resilience gemming (which we should be doing already anyway) without feeling as guilty for losing all that power.
Sustained damage will be as bad as always, but our burst will come up more often and as a result of power giving healing, exorcism granting 10% less damage taken and flash of light healing more we will be able to live long enough to see a second set of Wings.
Also the buffs Rogues, Unholy DKs and Ret received will potentially bring back the feared ret/rogue/dk cleave.
RBG-wise, still garbabe, your time will be better spent doing dailies until we get some AoE ability to justify our presence.
There's alot of useful little things you can do to enhance your play as Ret. For example, going into melee range 100% of the time isn't smart (and I see a lot of Ret's simply running in and humping melee [though it's ok to stick on casters]). It's best to go in melee range for Crusader Strikes, then get out of melee range til melee swing + crus strike are back up, kiting with prism / exo / judg until then in addition to supporting. Best time to stick on a target is when you pop Holy Avenger cause of the constant TV pressure.
I haven't played on the PTR but Vanguards as always is very informative with his videos (youtube WoWspotlight or SamK90), the new HoSac can win games and having the bursty FoLs back is great. 2m Wings is awesome too. A lot of Rets pop their Swifty and hope for a kill, when the best way to play is communicating with teammates to line up your burst when the enemy has no trinket or def cools up. It's definitely possible to support your team until you force your enemy trinkets, and that's when you should capitalize <3
Play the spec smart and observe the playing field and you'll boost your ability whether we're a burst class or not.
Basically, if you really REALLY enjoy the spec and PvP then Yes
I went warrior (See below) and after getting all my PvP gear I felt bored, had no desire to PvP all the time wishing I was a ret paladin (Maybe the only person to ever say that) I only play battlegrounds and the general chaotic nature of them allows anybody fully geared with a healer to run rampage on the entire battleground, Some do it better than others such as a frost DK (I assume this is because of their lower survivability)
The healing buffs are more than significant making ret probably the best hybrid burst healer with a selfless healer FoL crit on another target with wings up perhaps hitting for more than even holy can or at least damn close, if you like the sound of that, enjoy.