This is what really happend...
Activision wanted to reveal Modern Warfare 3 on March 2nd. One day after DICE finally reveals BF3 properly at GDC. FindMakaraov.com was definitely legit. Somebody at Activision saw what DICE has shown from BF3 thus far (which is almost nothing yet) and came to his senses and called off their reveal plans.
Activision and their many CoD-developers have nothing to compete with EA/DICE's offerings this year and they know it. All they can do is switching to damage control mode - like not going head to head with their reveal of Modern Warfare 3. Not directly competing with BF3 for as long as possible is their only move. A very smart move.
Way to save your face from public disgrace and not falling into the trap of linking the interest of your reveal to DICE's - Bobby K.!
*EDIT* Goeff Keighly got the scoop on the real REAL deal... dirty party pooper!
GameSlice - by Goeff Keighly - What is FindMakarov.com?