Extended Events are with out a doubt, my personal favorite amongst the new features in SQL Server 2008. Today my first whitepaper was published on the Microsoft web site as a part of the SQL Server 2008 Whitepaper's.
Using SQL Server 2008 Extended Events
This paper covers Extended Events, a new feature in SQL Server 2008 for troubleshooting. Extended Events offer a new methodology and framework for capturing diagnostic information from the SQL Server Database Engine. With a robust architecture, Extended Events sessions are highly flexible, highly configurable, and have a low impact to server performance. Event sessions are managed and configured using system and dynamic management views and DDL statements.
One of the key features of the Extended Events architecture is that a session can have any event with any action and write event data to any target available in the packages loaded on the server. Each of the targets provides specialized storage and consumption of data as events are fired. The integration with Event Tracing for Windows provides a previously impossible deep look into the inner workings of SQL Server with the operating system to properly isolate the source of hard-to-troubleshoot problems.
While not a complete replacement for existing troubleshooting tools and techniques, Extended Events in SQL Server 2008 provides an exciting new framework for database administrators and IT professionals to troubleshoot complex problems inside the Database Engine.