This time covers some of the new features in the WCF portion of Silverlight 3. You can get more details about everything here on the Silverlight Web Services blog.

• Proxy generation through slsvcutil. This tool is the Silverlight compliment to svcutil and works to generate proxies designed for Silverlight clients. Using the command line is an alternative to using Visual Studio for generating proxies just as in the desktop framework.
• Binary message encoder port. The WCF binary message encoder has been ported to run under Silverlight for improved performance when transmitting messages that have non-text content.
• Better support for the duplex HTTP channel. Proxy generation is now supported for duplex services using a callback handler for messages received on the backchannel. Type serialization is also supported when sending messages in both directions now.
• Transport security with username credentials. Passing credentials that are checked at the application layer while still using HTTPS for encrypting transmission is easier to setup and get working.