I think the Sith Empire is going to have a much higher population than the Republic side. Let's face it, they have the cooler archetypes. They the Vader archetype (Juggernaut), the Darth Maul archetype (Assassin), the Emperor archetype (Sorcerer) the Bobba Fett archetype (BH) etc. Vader, Darth Maul and Bobba Fett on one side in a Star Wars game is almost overkill. This is going to have a very adverse effect on PVP. I picture the Sith dominating PVP matches most of the time, and its going to be very hard for Republic players on PvP servers.
Glad I'm playing a Smuggler. Its going to be open season on Jedi.