Exchange team blogged about post TMG world. Read the blog at http://blogs.technet.com/b/exchange/archive/2013/07/17/life-in-a-post-tmg-world-is-it-as-scary-as-you-think.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

Microsoft Exchange Server 2010 Upgrade Guide