Well, finally we have managed to grab some time and start playing with the Enterprise Service Bus Guidance.
Biztalk ESB Guidance provides architecture and a set of Biztalk Server and .NET components to assist in the development of an ESB on the Microsoft platform.
You can download the bits and documentation at codeplex here
The guidance is well documented, but installation can be a little bumpy if you don't follow instructions carefully.
You will need Biztalk 2006 R2 installed and Dundas Web Chart (http://www.dundas.com/Downloads/index.aspx ) be sure to install Enterprise Edition.
