Who is making MW3 cuz im confused cuz they said IW was fired but idk?

Actually it isn't made by Activision, it is published by Activision. It also doesn't switch between Activision and anyone else each year. Every year the game is PUBLISHED by Activision. Then each year the DEVELOPER (the people making the game) switches between Infinity Ward and Treyarch (who made last year's Black Ops). MW3 is indeed being developed (made) by Infinity Ward. All of Infinity Ward was not fired; it was only a select few that were let go (mainly heads Jason West and Vince Zampella). The loss of these two is unfortunate as they were both very talented, but the developing company as a whole is still in existence and is creating MW3 alongside Raven Software and Sledgehammer Games.