If you go through the official website of Infinity Ward (an award winning developer of Call Of Duty and Call Of Duty 2), you'll find a vague listing about company's several major events that occurred on April 28th throughout history. The listing also indicates some major announcements on that day, giving some room to the rumor about revelation of very first detail about Call Of Duty 4.

Rumors are always a major source of information, may be this time as well.
Infinity Ward officials haven't yet commented on the rumor, but we are hoping an official confirmation sooner than later. We have to wait until next week, no other way ......!
Via: gamersreports