The new chat design includes a sidebar that lists the people you message most.
Create a Group Chat Instantly
Skype Journal lists the open questions about the Skypebook video calling. Here is part of the list of open questions
Video calling API from Facebook?
Video calling on the mobile Facebook app?
Video calling on mobile browsers?
Desktop browser compatibility?
Is the video p2p or does it go through central servers?
Are these calls subject to CALEA and other forms of lawful intercept?
Are these calls encrypted?
Are these calls using WebRTC and other emerging real-time web standards?