I still don't think Finn will end up using the lightsaber much. I think (and hope) Rey, who I suspect is the daughter of Han and Leia, will inherit it once Luke trains her in the force. I think she is who Luke was talking to in the second teaser, and it would be cool to see her wield it considering it was Anakin's, which would be her grandfather. In my opinion, only a Skywalker should use that weapon.
@mvtba All of that is no longer considered part of the official cannon. They call that material "legends" now. The only thing Lucasfilm now considers cannon are the films, the clone wars cartoon, and rebels. They will be completely rewriting events post ep. 6.
@KaptenHaddock I agree with you about the young characters. Specifically with the imperial officer guy. His name is General Hux. Dude is like 20 years old how is he already a general? Also yeah Kylo's robes do look a bit plain in the second shot, but he looks awesome in the first. Maybe its just the lighting.