The Community Tech Preview (CTP) of the CompositeUI Application Block has shipped! Download it today from MSDN here and start building those composite smart client applications!
Clearly the Patterns and Practices guys are truly living the Pattern Lifestyle and this block is rife with patterns such as the Model-View-Controller, Dependency Injection, Memento and Event Broker patterns. Understanding these patterns is key to understanding how this block works. So, to ease the pain for those of us who aren't pattern experts, the Patterns and Practices guys are holding a free training event to get you up to speed on this block. This is a two day instructor led event to be held here in Redmond on July 25th and 26th. More details here.