Microsoft have just released a new refresh build of Windows Live Messenger to testers - build 689. Some of the changes in this build include improvements to the color scheme and overall look and feel, Live Contacts, Messenger Add-ins, and Voice Call improvements.
Naturally, only provisioned accounts can sign into the beta. The build is available to download publicly as well as from Microsoft Connect.
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Windows Live Messenger Build 689 Refresh 
Linear Mode
