Via LXer, Phoronix announces that Microsoft has released Skype 4.1 for Linux:
No official change-log has yet to emerge for the Linux version of Skype 4.1, but the closed-source VoIP program now has the ability to sign into Microsoft accounts and also chat with Microsoft Windows Live users.
Skype 4.1 for Windows was originally released in 2009 and is now up to version Skype 6.0. The OS X version of Skype was also updated to 6.0 last month with Microsoft and Facebook account integration.
I think I'll let this one cool down a bit before upgrading anything.