I find the problems with pvp is what it has been right the way through, the battle system is just too slow to make it particularly interesting over pve content which would lead to rewards and the game itself never really seemed to be designed well for it.
I really beg to differ, and if you think combat is too slow in PvP, then you haven't really experienced it. Ballista can get very frantic when you have two full parties (or more). And fighting in parties is what FFXI is all about and when the PvP gets really interesting.

In the end if you want to pvp go play a game orientated for pvp and leave ffxi for pve.
Absolutely not, because FFXI's combat system is much more fun than any of those games.

PvP is only successful in WoW because you can get great gear out of it. If there were no good rewards, it would die out.