An upcoming demo has been announced:
http://matrixgames.com/news/852/Panz...Demo.Announced!
"The demo includes 6 missions from the Bootcamp Campaign, plus the invasion of Poland and the first few turns of the Norway scenario. The transition between the first two scenarios of the main campaign allows you to upgrade your army between scenarios and get a feel for how units improve and gain experience as they travel from battle to battle. Also packaged with the demo is a limited version of Panzer Corps’ powerful scenario editor so modders can try their hand at the near limitless possibilities for making new scenarios and campaigns!"