Facebook choosing Skype as the VOIP provider just caused a forced blend of your personal and business contacts. I primarily use Skype for business needs and keep Facebook for personal. In order to use the blended service effectively, I would need to add personal users to Skype and business users to Facebook. I imagine this will happen through Facebook Connect for authentication.
I imagine Skype has seen a bump in registration (Buzz Study article) and business when the announcement unfolded. If Skype unleashes Facebook Connect as an account creation and authentication mechanism, they look to double their user base. At the same providing Facebook access to highly desires business connection data. Imagine a system that shares contacts of over 1 billion people.
LinkedIn currently owns the business network connectivity and being able to create a social graph of business connections would open new doors for Facebook in advertising and revenue. While Facebook does ask your employment, it is not a focus and limits building networks around enterprises. LinkedIn would need to roll out a large set of features themselves to keep the focus on them as the business connectivity network. Would a move to Google Voice be the right choice for them?
What will you do? Start adding people to Skype? Add people to Facebook? Or let the system do it for you and cross pollinate your personal and business connections?