Anyone caught the show Haven yet? Interesting show (5 episodes so far) about an FBI agent who is assigned to find an escape con, she goes to Haven and sees strange unexplainable things and decides to stick around.
The story lines (like Warehouse 13, Eureka, 4400 and other shows that introduce new characters has endless possibilities) It seems this type of show does really well, unlike the shows that have fixed casts going down a linear path.
The twist in Haven, the lead character (arguably the FBI agent) is orphaned and finds a photo in a local newspaper archive from many years past of a woman who COULD be her - she believes she may have found her mother, although no one in town thus far knows more than a possible first name.
SyFy (I miss the Sci-Fi logo) does a good job at these shows. This one isn't as light hearted as Warehouse 13 but it fills a spot where more serious sci-fi shows have ran their course.