Now we know why there was no announcement of Eric Kripke's involvement with Supernatural's sixth season earlier today. The series' creator will not be continuing as showrunner when it returns in the fall but, apparently, he won't be gone entirely.
According to Entertainment Weekly's Michael Ausiello, Kripke will be stepping down from showrunning with the end of the current season, which also marks the end of his original "five year plan" for the series. He'll be replaced by executive producer Sera Gamble, who's been with the show since the beginning, but is said to be remaining with the series alongside his current co-showrunner Robert Singer, as "hands-on executive producers" who'll be working closely with Gamble.
Ausiello adds that part of the reason for the change is that Kripke is finalizing a deal with Warner Bros. Television that'll include his developing new shows in addition to his Supernatural duties.
'Supernatural' exclusive: Eric Kripke stepping down as showrunner [Entertainment Weekly]