Amazon.com now have season 4 of The Walking Dead for pre-order. No release date or info about a limited special edition has been revealed yet though.
Never read The Walking Dead Comics?
The comics are just as good as the show, plus the storyline is different. They're definitely worth reading! You can get the first compendium (first 8 volumes) on Amazon below.
Buy it here: http://amzn.to/1PPaDRR