I just received word that Matt Cohler, VP of Product Management at Facebook, will be leaving Facebook to join Benchmark Capital. Details coming shortly. There is now a lot of speculation about why Cohler would be leaving at such an important time for the company. With new products expected to be rolled out at the upcoming F8 event, it doesn’t make much sense. Kara Swisher thinks that it could be part of Sheryl Sandberg’s house cleaning effort.

Unfortunately there is not much else that can be assumed at this point. Leaving one of the hottest startups in Silicon Valley is bound to spark controversy but then again it appears that the venture capital firm that Matt Cohler is joining is rapidly becoming one of the hotter VC firms in the valley. The company has made investments in eBay, FriendFeed, Friendster, MySQL, Yelp and a number of others.

My guess is that we’ll never know what exactly happened but this is definitely an interesting move by Mr. Cohler. Mark Zuckerberg commented on the issue:

Matt is a valuable member of our team and one of our earliest executives. He has been an important contributor to Facebook’s growth and success and we are pleased he will continue working in a formal role as a special advisor to me and the Facebook management team.

While I’m note sure what a “special advisor does”, I’m sure that it will be a great position.