NCSoft announced that the 10th class, named Gunslinger would be added to Blade & Soul's Korean version on December 14th. Gunslinger is a dual wielding class.
Apart from that, there'll be new locations, continuation of the storyline, higher level cap and more abilities for existing classes.
Another big update as NCSoft revealed is that F2P mode is coming. That'll be on Blade & Soul KR servers, too. And it'll begin on December 14th.