I've found that playing as a tank in PvP is awsome so far. I still have considerable DPS despite using a one hander, and can completely wreck anyone in light armor.

The catch is crowd control. Any range player can easily take me down since they can all root me and shoot with impunity. But if I'm close or they are preoccupied, I can wreck havoc.

My recomendation is to have a healer back you up, and you can literally stride into any massive fight and be the last one standing. I've gotten into nasty battles of 10vs10 or more and just waded through, slamming my axe on any bright caster or rune priest I saw. Melee dps classes don't do signifigant damage, I can absorb most focus fire from spells, and my allies can have thier way while everyone is preoccupied.