Ryan Shoemaker has written up "Enabling Distributed Transactions Between Glassfish and .Net 3.0," announcing a screencast he's recorded on using WSIT Milestone 4's support for WS-Coordination and WS-AtomicTransactions. The screencast is more about invoking a Java service from .Net, but includes the transacted services. Here's what Ryan says about WS-Coordination and WS-AtomicTransactions:

Supporting these standards in our web services stack allows you to write fault tolerant applications that bridge across heterogeneous systems. Java EE developers can easily write applications that take advantage of distributed transactions that span multiple Java EE application servers (without needing WSIT). What WSIT adds is the ability to include transacted web service methods (think "container managed transactions for servlets") and also bridge across heterogeneous systems (think "Microsoft"). In a homogeneous GlassFish system, distributed transactions flow across RMI/IIOP. In a heterogenous web service environment, the transactions use the WS-Coordination and WS-AtomicTransaction protocols to flow transactional context and execute the two-phase commit protocol.

Distributed transactions and security are the most uncomforting parts of the WS thingy for me. Now I started to believe WS idea more. It even looks fun to start a transaction on the C# client and see it propagate to JEE so nicely. Presentation is really awesome, very clear. Thanks for the effort. -talip