When Supernatural creator Eric Kripke stepped down after the 5th season, Sera Gamble and Robert Singer took over as co-showrunners. It is now being reported that Sera Gamble will leave after the end of season 7.
According to Deadline, Being Human's executive producer and co-showrunner Jeremy Carver will be filling her spot and joining Robert Singer as co-showrunner. Carver was previously a writer and producer on Supernatural before moving over to Syfy for Being Human. As for the reason for Gamble's departure it is said that she decided not to renew her contract so she could focus on new project development.
Although not officially announced, Supernatural is expected to continue into its eighth season this fall. While we have no additional details on the future season at this time, we expect plenty of new information at this year's Comic-Con in July. Supernatural season 7 is nearly wrapped up, with the last episode airing on May 18th.