Call of Duty is the biggest media franchise out there, and it’s certainly one of the most popular game series around at the moment. For all the fans it draws in though, the series hasn’t seen any major alterations or changes since 2007′s Call of Duty 4: Modern Warfare. Series developers Treyarch and Infinity Ward have successfully followed the pattern of not fixing what isn’t broken so far, but Treyarch seem to be taking some rewarding steps into new ground with the upcoming Black Ops 2. Here’s seven reasons why these changes may well revitalise the franchise in new and exciting ways