Though AMC has not formally announced a fourth season, according to TheCitizen.com, TWD will begin filming in 2013. Here's the link:
http://www.thecitize...urn-senoia-2013
From the article:
Looks like America’s top-rated television show will be returning to Senoia and Coweta County for its fourth season. Stalwart Films spokesman Mike Riley made the announcement Thursday at the meeting of the Coweta County Commission as he thanked the county and its residents for their support of the AMC network’s hit show, “The Walking Dead.”
"The Walking Dead" will be coming back for a fourth season and will be associated with Senoia’s Raleigh Studios, Riley said, adding that pre-production for the show will probably begin in March.
Riley said that, along with being the most viewed show on television, "The Walking Dead" is seen by viewers each week in 120 countries.
Riley was at the commission meeting, as he had been earlier in the week at the meeting of the Senoia City Council, to thank Coweta commissioners, Senoia council members, the Coweta County Board of Education, the Coweta County Sheriff’s Office, the Newnan-Coweta Chamber of Commerce and Coweta residents for their support.
Riley’s thanks were on behalf of the cast and crew, Stalwart Films and the AMC network.
“It was a very successful season and we couldn't have done it without you,” Riley said. “It’s a big success and you guys are a part of it.”