I am a big fan of the book World War Z. Can't wait until the movie comes out. Looking forward to the action figures. In the meantime, I combined about 8 packs of the Gentle Giant Walking Dead zombie army figures along with two boxes of modern Marines from Armies in Plastic (www.armiesinplastic.com).
The Reinforced Square (RS) tactic is mentioned by Todd Waino as one of the most effective methods to dispatch the zombie hordes as the military takes back the United States. Todd also calls it the Raj Singh (RS) in honor of the Indian general who leads the fight against the zombie plague in India.
Hoping Gentle Giant makes more Walking Dead plastic "army" guys. A World War Z playset by any manufacturer would be pretty cool too.