It's not any surprise, but comScore has some new numbers reflecting the changing demographic of the Facebook community. People of means, the grown-ups, are flocking to Facebook, as well as teenagers escaping MySpace orbit.
As Facebook migrates beyond its core college demographic it will need some customization for each of its major demographic segments to some degree. What's appealing to teenagers isn't the same as what will keep the 35+ segment happy, which is now the biggest unique monthly user segment.
On the other hand, having an applications platform solves many of the problems of creating more unique experiences for each demographic. Even so, the core social networking platform, dealing with friends, networks and profiles, should continue to evolve and add functionality, such as features that apply to forming professional networks and managing those relationships. Just as Google has a majority of search ad revenue across multiple segments, Facebook could attain a majority of social network revenue by branching out into more segments, which is what shareholders value...and Facebook does seem destined for an IPO.
See also: Dennis Howlett: Facebook for the Enterprise = Facebook