LedZeppelin.comAn enigmatic countdown has begun at Led Zeppelin's official Facebook website and newly-launched Twitter page.  On Saturday, the word "FIVE" was posted on the sites, followed on Sunday by "FOUR" and on Monday by "III."  In addition, a brief video has debuted on Led Zeppelin's YouTube channel that simply shows the four symbols featured on the group's fourth studio album, accompanied by the sound of an audience cheering.

While many fans have taken to online forums to speculate that the band could be preparing to announce a new tour, others have suggested that that Zeppelin is about to reveal details of the release of a DVD of the group's reunion performance at London's O2 Arena in November 2007.  The latter scenario seems more likely, especially taking into account a Twitter message that the band's manager, Peter Mensch, posted on Saturday that reads, "It's almost here.  I've seen it and heard it.  Almost 5 years to the day."

Judging by the online countdown, Led Zeppelin fans should find out what the big news is by Thursday.

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