Finally, a book on the PDC release of Indigo - "Inside Indigo"
Saw this on MSDN, its finally here. The first book dedicated to Indigo, published by Microsoft Press.
MSDN has an article by the author (with one of the chapters of the book here).
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnlong/html/messagebus.asp
Note that - this is based of Indigo @ PDC.
For those who still read books :), this may be a good way to get a hang of the concepts. I would like to add though that we have had changes to the design the OM internally since the PDC. Most basic concepts are the same, so it wont hurt to get on the bandwagon. Before you ask me, it is unknown when we will publically release Indigo next for a Beta. :) All I can say is, its been a long wait for us too, and we also want to put it in your hands, don't worry!