Microsoft recently announced Silverlight at the Mix 07 conference. Now that its released I can freely talk about what I am working on. I am really excited to start working on the connected systems API's for Silverlight 1.1. If you refer to the Silverlight API Poster you can see that there are couple of API's marked "Soon".
I am in the team that will deliver the System.ServiceModel and System.Syndication apis for Silverlight. Its still too early to talk about the exact API's and functionalities we will be releasing under the namespace but the idea is to have the class complement the desktop API. You can install Silverlight 1.1 and develop apps using the API's currently shipping with the alpha. The alpha has support for HttpWebRequest (System.dll and System.Silverlight.dll) to make calls back to the originating domain. It also has XmlReader and XmlWriter support (in System.Xml.Core.dll) with which you can do Xml operations.
If you werent convinced of the possibilties of Silverlight, todays announcement of PopFly should definetly help. Popfly is built on Silverlight and aids in creating mashups using existing services very easily. Today was the first time I learnt about the Popfly project and am looking forward to adding custom basic "connectivity" blocks. Exciting times.