Looks like Rey's lineage will be explored...SPOILER

She was cloned from Aunt Beru's bones.

She may be the grand daughter of Boba Fett, and in turn a female product of the Jango Fett clone line.

But she doesn't look like any of the major characters from the first six movies! Even if they've somehow managed to change the sex of human clones, you'd still think the clone would look like the original person, and she doesn't bear a strong resemblance to Luke, Han, Leia, Anakin, Padme, Obi-Wan, Lando, any Fett, Dooku, Mon Mothma, Qui-Gon, Shmi, Uncle Owen, Wedge, Palpatine, Mace Windu, Yoda, or Chewie. She's even a foot too tall to be cloned from one of Padme's ladies-in-waiting!

Although given the choice, I'd love for her to be Palpatine's clone. I loved that old queen, I'd take him back any way possible...

She's probably Susan Boyle's daughter.

She grew from the lost hand of Luke :D