When I was on my break, I saved a link to the SWTOR forums posted on Twitter by Zelibeli. The post talks about the distribution of player guilds that have been pre-registered and shows that there are more guilds/players on the Empire side than the Republic. That alone is interesting since in most MMOs the “good” guys usually end up with more players, although I think that has more to do with which side tends to have the uglier character models.
Even more interesting was the distribution of players by faction and sever type.
Type Empire Republic Total PvE 17327 18262 35589 PvP 31556 15093 46649 RP 4819 8049 12868 Totals 53702 41404 95106
There’s very little difference in strength between the factions for PvE rules, but Empire players dominate PvP and Republic players out number Empire 2-to-1 in RP.