Go check arena junkies for confirmation & ladder standings.
I love my Prot, hence I play PvP as prot - but in any competitive context, Prot has been killed by Blizzard who (whilst maintaining battleground mechanics that strongly endorse the ideology of a tank presence) don't believe in keeping prot actually viable in PvP as any sort of priority.
In fact, GC himself said the following on the subject recently :
"We want the Protection specs to have a place in Arena play, but to be frank, it's not our highest priority. Our sense is that most players who chose Protection chose it for tanking.
We don't want Protection dps to be trivial, but we also don't want it to rival that of say mages and rogues even in PvP. A Protection class in PvP should be more about survival and control, not about massive damage. With the added focus on BGs in Cataclysm, the tanking specs will be good at flag defense or flag-carrying, which suits their strengths.
The Vengeance mechanic is a way to help us balance tank damage. It can be as high as it needs to be in PvE, while much lower and most-importantly dispellable in PvP. Ghostcrawler
Lead Systems Designer" 05/07/2010
Since the release of Cata though, prot spec pallies have fallen by the wayside, with the recent nerf to WoG being the final nail in the coffin. Not only do Prot pallies hit like a sad, wet noodle and can't down a half decent healer 1v1 if their life depended on it, in terms of being a real defensive spec in BGs (ie flag carrying) they are in fact the very worst PvP tank spec option in the game at present. GC and his development team nerfed Prot into the ground and the larger pally community are in an uproar over the issue on the official forums. Some have been light hearted about it all though...
If you are hell bent on some damage spec, Ret is still the way to go, although the recent WoG nerf absolutely pounded that spec into the competitive dirt as well and many high level Ret players have actually quit the spec as a result, citing this as the straw that broke the camel's back.
Whilst Holy spec is getting a very minor speed buff in the next batch, there's still issues over this spec with many high level arena teams preferring other healers to achieve a rating.
In short, holy is the only real semi viable spec for competitive PvP for the pally class in the immediate future, but if you're content with just playing for laughs and giggles, you pick whatever style suits your personal playstyle best and roll with it.
Between Ret and Prot specifically for PvP? I'd pick Ret if you want to be competitive.
Prot is more or less just for fun.Cata is a fairly dark period in the meta cycle if you are a Paladin player. After our moment in the sun during wrath, Blue have a very conscious and active roll in trying to 'encourage' the former flavour of the month rerollers into a new class.
Because regardless of the rhetoric and negative sentiment from the Paladin faithful, the rest will dutifully extend their subscriptions in order to level up a new character.
It's all a question of business at the end of the day and nothing to do with any honest intent to balance the game.
By all means, play Pally in PvP if you are determined to stick to your class, but if you want a Damage dealer or Flag carrying class, you're better off with a Warrior or DK which are both better suited and more favoured by blue devs in the current meta.
Sadly, Blizzard doesn't offer a paid class transfer service, else I'd have moved on already.