Jensen and Danneel Ackles announced that a prequel is now in development with the network [x].

The prequel, titled The Winchesters, will follow the story of John and Mary Winchester, Sam and Dean's parents. Jensen will reprise his role as Dean and narrate the story. Him and Danneel will executive produce through Chaos Machine Productions [x]. The full article can be found here.

While many fans are, uhm, disappointed, some point out that, according to Jensen, it is the first story they wanted to tell, which suggests that there might be other ideas and plans, including a reboot [x]. However, most fans are not too happy about the prequel. John and Mary have already been told to not having liked each other before a cupid got them together, so that Sam and Dean could be born to play their part in the first apocalypse. This, plus the general dislike for John felt by many fans and the hopes for a reboot and continuation of Supernatural, causes the general reaction of "please no, why would you do that." Many are disappointed that Castiel most likely won't make an appearance, considering that he joined Supernatural in season 4. That doesn't stop Misha though.

Currently different tags, including 'john winchester,' 'John and Mary,' 'Danneel,' and 'Jensen' are trending worldwide on Twitter, as well as 'Wayward Sisters.' My condolences to the Twitter Intern.