Star Trek Online has updated their FAQ. INcluded in the update is some new information on the available factions in the game, as well as a new race list.
What are the playable factions?
At launch all players will be part of the Federation with playable opposing factions coming via expansions. Players will be able to align themselves with one of a number of both mainstream and fringe groups within Starfleet. A player's alignment will have an affect on the types of missions available as well as access to unique technology and racial equipment.
Read the FAQ, here.