JJ Abram's Alcatraz Showrunner Exit

It seems JJ Abrams' produced TV series Alcatraz has experienced a bit of a bump with the co-creator of show stepping down as executive producer. No reason has have been given nor any indication if it was her choice or Fox's. She will be replaced by Jennifer Johnson (Cold Case) and Daniel Pyne (Fracture). The series is expected to premiere sometime early 2012 but no date has been set.