wat will it really be???

it depends ince SM are all the rage for PVP nowadays but they rarely get chosen for dungeons and TMQ's, being powerful doesnt necessarily man doing the most damage since even an SM can be beat if a strategy is used.

so your sayin it can be any class and it only matter ur damage and ur strategy

There shouldn't be any over powered classes. Not if it's a good game. However, Dragon Clan Namekians, for a short time, were indeed over powered.

If your talking PvP wise then there already is one, it's called a Sword Master. Though before 1.0, it was the Dende Priests but they got nerfed. :P

PvE wise its the Grand Majins. Their Spin Attack can take out hordes of mobs in one go.

It depends on your knowledge on them, for example; If you know Spiritualist (Crane or Turtle) absolutely perfect and know every strategy and know what stat and bonus to have, then Spiritualist (Crane or Turtle) would be your best choice. Unlike WoW, where Retribution Paladins were absolutely overpowered, DBO has more balanced classes :)

As a fighter (currently lvl 39 mostly played in 1.5 patch), I've yet to lose to a swordmaster class when I duel waiting for TMQs. To try and say which is the best pvp class at the moment is quite hard and is not really determinable right now I would say. Usually it's just the stronger player or more knowledgeable player. The characters' skills play the biggest role in pvp, then character level, then equipment, in that order of importance I would say.