After a fairly long period without new GlassFish Podcast episodes, here's an interview with Harold Carr, the architect of the unified GlassFish Metro Web Services stack. This 20-minute discussion covers a brief introduction, uses-cases for using secure, reliable and potentially transactional Web Services, tooling, and more.
The Metro stack is available to use in both GlassFish v2 and GlassFish v3 Prelude. In the case of the later "Prelude", the only difference is the need to add Metro support from the update center (web admin tool, updatetool UI, or pkg command-line). Also, as explained in this comparing GlassFish v2 and v3 Prelude table, you'll see that interop with Microsoft .Net 3.5 requires Metro 1.4, which is available from the update center.
You can find more content on Metro in the Java Web Services tutorial, and, of course, on the Metro project web site. Further entries on TheAquarium are tagged with the Metro tag.