A new al Qaeda propaganda ad, headlined "Wait for the Big Surprise" and featuring a digitally altered photograph of President George Bush and Pakistan's President Pervez Musharraf standing in front of a burning White House, was posted on the Internet today.

The brief clip from al Qaeda's "as Sahab" propaganda arm juxtaposes the doctored photo of Bush and Musharraf along with previously seen images of al Qaeda's top leadership -- Osama bin Laden, Ayman al Zawahri and Adam Gadahn -- as well as a photo of an SUV in a motorcade.

There is no additional information provided in the ad, and it closes with the words, "Soon -- God willing," written across the screen and repeated several times.

Following the recent failed London-Glasgow terror plot, U.S. intelligence officials have been paying closer attention to the now frequent propaganda releases from as Sahab, studying the videos for hidden clues or signals.

The full video is expected to be released on the Web in the next 24 to 48 hours.