On Wednesday, Facebook's Mark Zuckerberg will sit across from ABC News' Diane Sawyer in his most high-profile interview since 2008, when Leslie Stahl interviewed him on 60 Minutes.

Facebook's well-known CEO doesn't give many public interviews, and for good reason: He has melted under the lights before, most prominently at this year's D8 Conference. When Zuckerberg agrees to an exclusive, national TV interview, you know that he has something important to say.

What message does Zuckerberg want to convey to the American public? To the entire world?

Changing the Narrative

We fully expect Mark Zuckerberg to use his national stage appearance to announce that the world's largest social network has more than 500 million users. It is one of the most significant milestones in the company's history, plus the timing fits.

The national stage gives the young CEO the opportunity to rewrite the Facebook story — one currently being written by this year's privacy fiasco, the upcoming Facebook movie and Zuckerberg's poor performance at D8. While the social network continues to grow wildly, the narrative of Facebook changing the world has veered off course.

Bringing Sawyer to Facebook headquarters does several things. First, it humanizes Facebook by showing off a determined, smart, happy team. Second, it provides Zuckerberg a chance to cast himself in a positive light and make himself into a likable character once again. Finally, it's a chance for Zuckerberg to get his message out direct to the people, past the media and the blogosphere.

While Zuckerberg's big announcement is likely to be the half billion user milestone, the focus of his message is more likely to be on the utility and connectivity of Facebook, and the positive world-changing impact it has had on our society. If he's smart, he'll bring out stories of how Facebook has reconnected families and friends, as well as talk about the connected future that he envisions.

That positive message is what Facebook's CEO will try to deliver. If he can avoid major snafus, he'll succeed in repairing at least some of the damage that's been inflicted by the company's previous missteps.