Perhaps in the Star Wars: Battlefront beta you got a chance to play as Luke Skywalker or Darth Vader, to of the characters that are unlockable as powered-up "Hero" and "Villain" specials in certain modes. EA had also previously revealed Boba Fett (he falls on the villain side), and today, hot on the heels of Star Wars mania last night, they announced three more characters added to the line-up.
Leia Organa is a support play character, who can buff her teammates and hold positions. When Leia is active and a player respawns, they'll also have a boost, spawning as Alderaan Honor Guards, so when she's activated the whole team of Rebels gets stronger. She also has a suped-up blaster that takes out stormtroopers more quickly. One power move is a boosted shot called Trooper Bane that gives a one-shot kill to stormtroopers and will stun Villain characters. Another is the Enhanced Squad Shield that stops not just blaster bolts, but even some Force abilities. Supply Drop rounds her out, which acts as advertised, dropping powerups and health boosts.
Emperor Palpatine is the third villain character, and yes, he has Force Lightning, a very powerful area effect attack. Chain Lightning is the upgrade that extends his reach. Force Dash is an extremely rapid-move to bring him into a group of Rebels (good to chain together with some Lightning. Sorry.). He also has a support ability like Leia's called Imperial Resources that does the identical thing, but for the Empire.
Finally, Han Solo rounds out the initial three Hero set, a "gunslinger mainly designed for lone wolves," as the announcement describes him. He's essentially a Rebel trooper with much stronger attacks, so if you're already used to playing as a member of the Alliance, he'll be easy for you to master. His three special abilities include Rapid Fire, which allows for quick shots (as fast as you can pull the trigger) with no overheating. Lucky Shot is a charge attack that works great against any enemy: Infantry, Villains, or even vehicles. Finally, the Shoulder Charge lets Han slam into action, taken right out of A New Hope.