Microsoft has a couple of interesting interop webcasts coming up. Registration is free and open to everyone.
First, there's a "level 300" webcast on Windows Communication Foundation (WCF). It is entitled, Learn The ABCs Of Programming Windows Communication Foundation (WCF). Scheduled for September 11th, 2006, from 11am-1230pm Eastern US time. This isn't interop per-se, but it does cover WCF, the fundamental communications programming framework for Windows. WCF does WS-*. It's critical to understand WCF if you are building systems that run on Windows that must intercommunicate with apps that run on other systems, or apps that are built on non-Microsoft frameworks (example, Apache AXIS running on Windows). Surely there is lots of WCF information out there, this is one additional webcast.
Next, we have J2EE and JEE5 Interoperability with .NET. Another level 300 session, this should be pretty interesting, with some updated material. It's given by Mohammad Akif, who works for Microsoft, but previously worked for Sun Microsystems, and co-authored a book on Java and XML, entitled Java XML Programmer's Reference. This webcast is September 12, from 1-230pm Eastern US time.
These are part of the Unwrapped for Financial Services Webcast Series for Developers. It is the 3rd such series, these have been well received. While the material is specifically intended for use by developers in financial services, it will be interesting to others as well. If you want to see the entire series content, go to http://www.financialdevelopers.com/ where you can browse.
By the way, "level 300" means, pretty technical. For the WCF talk, it probably means that attendees are assumed to understand .NET development, understand basic software system architecture concepts like pipelines, chaining, and interceptors; and be pretty savvy with VB or C# code. You're also going to need to know what is meant by "XML Infoset" and you should be familiar with WS-*. For the JEE interop talk, it means attendees should probably be aware of XML parsing frameworks in Java, as well as WS-*, what XML serialization (aka XML Data binding) means and how it works in general, and so on. You should expect lots of angle brackets and code in both these sessions, I'm guessing.