Acording to Showbiz 411, the call is for three main roles which have previously been listed alongside others on a casting call for Episode VII, which suggests that some roles have already been filled.
The roles are:
Young Man - Early 20s. Handsome, but not necessarily heroic. He is witty and smart. Physically fit.
Man - Late 20s. Physically fit, handsome and confident.
Young Woman - Late teens. Physically fit, raw energy, independent with a great sense of humor.
Could these be the offspring of the original stars of the classic trilogy?