...Meh
CoD makes for good, polished, safe games. Sure I'm sick of every publisher and their brother making a long string of clones, but CoD...that's there thing. They make these linear, cinematic shooting galleries with interesting set pieces. They make the Die Hard of video games. Ill put something like Portal 2 on the pedestal long before CoD, but with every CoD game, Ill get a few dozen solid fun hours of explosions and cathartic violence. They do a lot of things right design wise, and there's a reason there mechanics get copied. Adding some innovation, great, but please keep focused on the basics.
My only concern is the non-linear bit. Non linear stuff is great and all, but strict linearity can lead to a much more tightly focused, well paced, and enjoyable story, and overall linearity serves the CoD style well. Nonlinearity and sandbox gets thrown in as buzzwords and reduces a game to a giant mess. I can"t name a single game that had non linearity added to it, and didn't see that weaken the game.