I interpreted that as part of their legal obligation to add eavesdropping capability to Skype, which was probably quite difficult with the more decentralized network. But overall, I'm pleasantly surprised by the number of pleasant surprises coming from Microsoft lately.
Lawful intercept could be added without routing all traffic to their nodes. Perhaps MS correctly realised that offering a service which uses arbitrary amounts of computing and bandwidth from users is a crappy thing to do and not in-line with an MS offering?
