IT IS FINALLY HERE!  Keenan just posted that the The Definitive Guide to the Microsoft Enterprise Library will be shipping November 26th.  It has been a long time coming.  While I played my small part in the initial writing, Keenan spent a lot of time trying to keep up with the face pace of Enterprise Library releases and still keep his day job.  I encourage that you go out and pick up a copy.  I know for my part I tried to make sure that it contained as much information as possible to extend the EL as well as how to use it out of the box.