Being a huge CoD fan I too am pretty ticked. Mattinator is correct and yes Infinity Ward is making the next CoD, which as far as I know is PC exclusive.
Latest intel says it is going to be "Modern Conflict", like Ghost Recon and Rainbow Six, featuring Navy Seals, SAS, Green Berets etc. It's supposed to be more realistic this time around, ie no regen health, wepons more lethal. With destructible environments, and all the modern gadgetry you'd expect.
Plus vehicles.
A few months ago on google you could see an article about all this, and this is all I remember. I cant find the site again for the life of me, and this is merely a rumour so only time will tell. Personally I don't care WWII or Modern too much, just as long as multiplayer involves good teamwork and the gameplay's good.
EDIT: Managed to find this, isnt original link I saw but as you see again two CoD games, Treyarch making the console one and Infinity -> PC
http://uk.codejunkies.com/news_reviews. ... =39&Page=3