Buzz has been building that Facebook's product announcement event, which is being hosted at its headquarters today, will be the unveiling of a video sharing function for its Instagram photo-sharing service.
Facebook has kept the news a secret, but has been dropping some hints. The iconic "Like" symbol that stands outside the entrance to the company on Hacker way has been covered with a banner reading "a small team has been working on a big idea."
And this morning I snapped this photo of an bright orange empty newspaper vending machine, and a black chalkboard with the logo for a company called Blue Bottle Coffee drawn on. Facebook has been dropping some heavy coffee references, with the invitation saying "Join us for Coffee and learn about a new product" and a coffee cup stain on the corner of the paper invite.
(Read More: Facebook Event: If Vine-Like Vids Hit, Cash Will Follow )
Another potential clue to today's announcement is Instagram-related. Last night, CEO Mark Zuckerberg—who has only posted ten photos ever to Instagram—posted a photo on the service for the first time in six weeks.
Speculation has been building that Instagram will unveil a video sharing service for its 100 million plus users, as video ads become more valuable, and as Twitter's Vine, which allows users to share 6 second video clips becomes more popular. The challenges for Instagram: making videos look as good—and as easy to scroll through—as photos.
(Read More: Six Things You Didn't Know About Twitter's Vine App )
The pressure is on for Facebook to catch up to Twitter's Vine: it grew to 13 million users in just 4 months and sharing on Twitter of Vines just surpassed sharing of Instagram photos. Anticipating some news today, Twitter said earlier this week it would unveil some new vine features.
Even if Instagram videos aren't announced today, we expect them later this year. And no matter what's announced we expect a lot of questions about how it'll impact users and revenue.
—By CNBC's Julia Boorstin. Follow her on Twitter: @ JBoorstin