i like that, but imagine how that look with a 5$ usb cam in a low light bedroom what is missing is the fotoshare function of msn. but i fear this excelent design will never make it, as microsoft decided for the childisch stoneage tile stuff, which is a kick in the ass of all the user got a new Computer or Grafic card to be W7 Aero ready.
Nice work! Not sure about the way the tabs look though. Not really liking the gradient/shadow thing going on there. Also, how would you add someone to the conversation so you could have like a 3-way chat for instance? Also what font are you using mostly? Is it Segoe?
I really hope Skype adds Windows Live Messenger's "activities" so you can play games, share desktop, remote assistance, etc.