There’s a new Pattern and Practice out: Application Interoperability: Microsoft .NET and J2EE. This is complementary to the .NET and J2EE Interoperability Toolkit by my teammate Simon Guest.
FYI, I have links to many of the Patterns and Practices under “Architecture” on my Linkroll. This new one is under “Guidance”. There are also sections for Application Blocks, Lifecycle Management and Patterns.