A mysterious posting on the official forums over at Infinity Ward has fuelled speculation that the studio is about to announce that Call of Duty 4 is in the works.

The thread topic, started by one of the site's Administrators, lists a number of significant events throughout history that have taken place on April 28, from the birth of the United States' fifth president, James Monroe, in 1758, to the invention of a cure for yellow fever in 1932, ending with: "2007 - What goes down this April 28 is equal to, if not surpasses, the magnitude of any of those."

With Infnity Ward and Treyarch seemingly taking it in turns to develop the hugely successful World War II first-person shooter franchise, common sense would point to the probability of the former to be working on the newest in the series. While the previous three iterations have been set in World War II, early reports suggest that Call of Duty 4 will be set to the backdrop of a modern day battlefield.

Here's the message in full:

"Insert boring update about some mundane 'what we're doing' detail that no one actually cares about (such as new employees or kleenex testing) because they're just reading these updates for the glimpse hope that we'll slip and say something we're not suppose to about our next title, or that we're going to allude to the fact that maybe, just maybe something that actually is interesting is coming up in the near future (and by near future I mean next Saturday).

Amazing Things To Happen On April 28th:

1758 - James Monroe, 5th President of the United States is born.

1788 - Maryland becomes the seventh state to ratify the Constitution of the United States.

1932 - A vaccine for yellow fever is announced for use on humans.

(Then nothing really happened for a long time.... but now....)

2007 - What goes down this April 28th is equal to, if not surpasses, the magnitude of any of those.

Whose ready?!"

Surely that should be "who's", no? The writer must have been really pumped!