http://www.eurogamer.net/articles/2016-10-04-understanding-divinity-original-sin-2-in-early-accessFour of the planned six origin characters are in the game now. Those remaining are the undead origin character and the dwarf, says Vincke. In addition there will be default racial origin stories for people who make their own character from scratch, so however you play you'll have an origin story to pursue - as of course will the people playing with you in multiplayer, or the AI companions playing with you in single-player. And these are stories that weave far into the game.
Just thought people would be interested in hearing a solid number before too many get their hopes up.