Personally, and even though Yoshi-P has stated that classes will be receiving more abilities in 2.0, some being added with PvP balance in mind... the whole "rock paper scissors" that the current class design would be rather interesting to think about in a PvP environment.

Similar to how PvE battles are currently, where there are different setups depending on different boss mechanics, it will be interesting to see how PvP teams adapt and react, which builds will be the most used, etc. It would be interesting if you were allowed to change classes in a PvP battlefield for example, to see if teams were allowed to change their strategy dramatically on the fly.

While I can understand that some people would want every class to be equally viable in every PvP scenario - in a game that lets you level every job/class on a single character, and lets you adapt to any situation as long as you have put the effort in... There is less need to balance each class individually and this allows the jobs and classes to maintain their individuality and unique flavor.

As much as I know people hate seeing "WoW" used as an example on these forums, the game was ruined for me personally at the end of Sunwell, when they chose to homogenize the classes. I played a Shadow Priest at the time and I loved being a mana battery, a true support role. I didn't feel the need at all to be competitive DPS wise, I loved my niche role. That was taken away from me, and so I lost interest.