MSFT's Application Architecture Guide 2.0 Beta 2

Microsoft Patterns & Practice team has recently released the beta 2 of the Application Architecture Guide 2.0 offering significant changes from Beta 1 among which are

Technology matrixes for choosing technologies like Presentation, Data Access, Workflow, and Integration technologies. 
New Agile Architecture Method 

Tuned and pruned the recommendations across the entire guide. 
Restructured the guide for simpler parts 

Read more about the changes at J.D. Meier's blog