I think there will be at least 3 factions and maybe 4. Each faction will have certain profession/classes.

Remember that during the Jedi vs Sith Wars, there were non-force sentistive people who faught on both sides. So the possible factions would be Sith, Jedi, Mandalorian and maybe Criminal Underworld.

With in the Jedi and Sith factions, you would have certain force sensitive specialties like in KOTOR 1 and 2. The Jedi/Sith would not be cookie cutter like in SWG. post NGE. Within those two factions, you would also have non-force senstive professions, like soldier, officer, pilot, etc. The Madalorians were jedi killers, so they would have to be pretty bad ass. Within this faction you could have commandos and bounty hunters that can kill people in all factions. The Criminal Underworld faction can have professions like smugglers and such. The jest of what I'm saying is that Jedi and Sith wouldn't be classes, so much as factions. If you choose to be a Jedi Knight or Sith Lord, you would have a lot of customization. You would need to specialize. Although Jedi and Sith are powerful, they can be defeated if the other professions have the right equipment. Soldiers with Cortoise armor and weapons would be cool (I read this in one of the Darth Bane books.). I know Bioware will do a good job. We'll just have t wait and see what they come up with.