Heh, wow people are more out of touch than I thought. That world event has been around for a long time. The most recent addition was Keys and Organs to get a Hellfire torch.
Popular PvP Characters:
Smite Paladin- Dominates Melee combat and can take out sorcs with ease using Charge. A smite pally with Grief and an item that lets you cast the Necromancer curse that turns your damage into life is nigh unstopable with the right gear to switch out.
Trapsassin- Does very well at PvP with the use of lightning traps and appropriate +light damage gear. Needs lots of +1 skill charms to be most effective. Also having Enigma is highly recommended for avoiding being hit.
Poison WW Sin- Using a certain runeword claw, assassins can make use of the barbarian skill Whirlwind. Add to this tons of poison damage through skills and charms and you've got a very good PvP character.
Glass Cannon- Though not as effective as they were in 1.09, bowazons using guided arrow can still do a decent amount of damage, however they are very gear specific. Put only enough points into Str to sue your gear and dump everything else into Dex. Grab yourself a rare Grand Matron bow and armor/ helm outfitted with x7 40/15 jewels. Fire away. You do lots of damage fast but beware, you will die in one hit. Luckily the dodging skills save you more often than not.
Light Sorc- Very feared are these sorcs unless you have the right gear to face them (stack light res+absorbtion gear) with enough +1 light skill charms these sorcs can pump out the damage fast while still being highly maneuverable using teleport without having to resort to using Enigma.
Blizzard Sorc- The cold sorc has gotten several good upgrades since 1.09, frozen orb is no longer the way to go. With all of its synergies, Blizzard can often 1 hit KO anyone who stays around long enough to take the damage. Like the light sorc, these sorcs can easily be countered by using stacked cold res and a very common PvP ring, Ravenfrost.
Whirlwind Barb- Barbs have a very deadly combination at their disposal with the 1.10/1.11 runewords. The most common of which is Beast, which grants the paladin's fanaticism aura and Doom, which grants the paladin's holy freeze aura. Unlike most other forms of cold damage the holy freeze bypasses the "cannot be frozen" effect from items giving you a massive speed advantage against anyone who gets close enough to you. Combine this with Battle Orders for a massive life total and Whirlwind and its GG.
PnB Necro- I don't have much experience playing as one but against them they are a real pain for any melee character. PnB necros do a high amount of non-elemental damage through the use of bone spear and occasionally bone spirit. There are very few ways to prevent this damage. PnB necros also make using of bonewall to obstruct the path of advancing melee characters which makes it particularly difficult to actually hit them. They also like to use Enigma to make quick getaways.
FoH Pally- The FoH paladin makes use of his Conviction aura to lower the resistances of his target, and they attempt to instantly kill them using Fist of the Heavens, an auto target skill that only requires that you click near the opponent. I have never found the FoH pally to be useful on its own in high level PvP, but its fun to take one into Hardcore mode and 1 shot the characters that won't be coming back to life
The Hammerdin- While the Hammerdin is the god of PvE, they aren't too bad at PvP, assuming you can get people to walk into your hammers. Playing as a hammerdin usually works 1 of 2 ways. The first is to plan your field of hammers and try to herd the opponent into it using a combination of charge to try to desynch them and launching 1 or 2 hammers to try to send them into your main field of hammers. The second way is using enigma and teleporting directly below them and the letting loose a hammer or 2 and then teleporting away. If you hit them with both hammers 9 times out of 10 you will have killed them. It it fairly difficult to PK with a hammerdin against ranged characters especially since you have to stand still to cast your hammers leaving you momentarily vulnerable to AoE attacks such as Blizzard.
Wind Druid- Using a combination of... I forget the name, Hurricane? Basically you surround yourself with a hurricane, summon some wolves as fodder for melee characters, teleport on top of your opponent using Enigma and then blast away with the non-elemental damage of Tornado. This build works particularly well against spell casters, as you have a windshield that negates a certain amount of elemental damage.
Thats all I can think of for now, those, I believe, are the most common in high level PvP.