The Walking Dead is one of AMC's biggest hits, and once Mad Men and Breaking Bad finish their runs within the next year, it will be the network's marquee title.  Since new concepts are risky, AMC is going to as close to a sure-fire bet as they can get with another Walking Dead (in addition to the "Better Call Saul"/Breaking Bad prequel series).  Variety reports that author Robert Kirkman and executive producers Gale Anne Hurd and Dave Alpert are working on a "companion series" (is this what we're calling spin-offs now?) that would air in 2015.  The new series would feature a new story and new characters, but presumably the same 'ol rascally zombies.  Kirkman added that the new series would be completely from scratch and not from his comic books.

The fourth season of The Walking Dead will premiere on October 13th.