The PVP is really very good already in SWTOR apart from Jedi Knights being too weak.
It is similar to vanilla/TBC WoW PVP but without the ability bloat and ridiculous class balance issues of Cata, and it is slower paced making it more intelligible and more watchable as a spectator e-sport.
Arena in SWTOR would be amazing and very fun to watch and play, with a single 4v4 bracket being a natural fit.