As part of Microsoft's routine, monthly security update cycle, we released 13 new security updates on December 13, 2011.

Get the details at http://www.microsoft.com/security/pc-security/bulletins/201112.aspx

Read my favorites blogs:

Designing a backup less Exchange 2010 Architecture

Step by step guide for upgrading Active Directory from Microsoft Windows 2003 to Microsoft Windows Server 2008

Microsoft Exchange 2010 CAS Array – Steps and Recommendations

Appear Offline in Microsoft Office Communicator Server 2007

Microsoft Exchange 2010 Test cases

Microsoft Exchange Server 2010 Disaster Recovery