I've finally shipped the Adapters chapter of Professional BizTalk Server 2006, which makes 3 chapters done and plenty more to go :(
The chapter specifically doesn't cover writing Custom Adapters or the underlying Adapter architecture as I've taken the call that BizTalk Unleashed contains the "bible" of Adapter Development written by Kevin Smith (who I like to think as the godfather of that area :)
I discuss the myriad of Receive and Send Port magic and drill into each Adapter providing background on when you should and shouldn't use them (MSMQ vs MSMQT for example), the context properties promoted and provide a walkthrough on developing and configuring the FILE, WSS and SOAP Adapters and with the SOAP adapter I explain how to effectively create the message required to send to a SOAP adapter with a complex-type (i.e. class).
Plus with our announcments around BizTalk Server 2006 R2 it looks like I'll be modifying the book in a number of areas to make it cover R2 (especially with regard to WCF) and will ensure it's bang up to date when it hits the shops early next year.
I've had to replan the chapter ship schedule as I'm a bit behind :) but I'm still on-target to meet the original end date and I've got the BizTalk Architecture chapter to ship before I go on holiday early July!