I took the plunge yesterday. I have a low level warrior in a PvP server which I started as an experiment to see how the PvP server and PvP in general would feel like.
The mentality is a lackluster. Sure, the feller is still in the first bracket of WSG (lv10-19), so I haven't met any real 'world pvp' as of yet. In addition to this, the starter areas are void and empty: I've seen a handfull of players in my journey to the Battlegrounds, even the big city is pretty quiet.
But the PvP... I've stated earlier that the game is too gear centric to be interesting in PvP: the one higher in level and with better gear wins, always. That's the way it simply is, there is no avoiding it. The guy who has had the luck to gain blues (or heirlooms, for the matter...) has the upper hand to the Jack the Rabbit who has plunged through the mud to get where he is.
As if that wasn't enough, the system is playing the game, too. I mean in ruining the PvP. As you are roaming in the battleground, you can hide behind a pillar, wall, tree stump, what not. But you cannot really hide, as your nameplate shines like a star above you. Not only above, but through the walls and floors of the flagrooms!
Frustrating to be ready to ambush an opponent's player who just stops dead right before you are about to pounce on him/her, and starts the last preparations for your demise. To which you cannot get in time to disrupt the preparation.
Then again, you might get lucky. I won a one-on-one against a 4 level higher player, barely, but still. My warrior beat that rogue good.
That's the only thing that has made me feel good about pvp so far.
The other thing completely is the hacking. In WSG at low levels you can still find the speed hacks, which enable the player to cap the flag within few seconds after the game has started. Obviously the hack is faulty, as the player cannot reproduce that feat after the first try. Or the guy using it was just a dumb schmuck in addition to the fact he was hacking.
What bugs me most about the hacking is the fact that it ruins the game for all the players in the battleground: the opposition feels cheated, the team mates feel cheated and the dumb bugger gets reported.
So to make the PvP in WoW is IMO a big joke, with no real skill needed, just enough butt to get the best gear for the job before entering the battleground. And then relying on the fact that the rest of the team thinks the same about working in the field of glory.
Which they most probably will not do, anyhow.
Can't say anything about the arenas, but I presume the gearing component is present in there, too, and in as great extent as in the normal bg's.
We'll see, if I ever get that far. I'm more inclined to the PvE grind than the PvP one.