From James Clark on the Expression blog:

I'm pleased to announced that we just pushed a preview of the SLS publishing plugin for Expression Encoder 2 live:

http://download.microsoft.com/download/2/2/a/22a8da23-ffa7-4e5a-8fed-8239d3a7b322/SLSPlugin for Expression Encoder 2.msi

This plugin makes it very easy to publish and manage your encoded Silverlight video experiences online via the Silverlight Streaming service from within the Expression Encoder application.

Having used the SLS plug-in for Expression Encoder 1.0, I installed this as soon as I heard about it. Looks like there are some nice enhancements to the plug-in, on top of the nice enhancements in Expression Encoder 2.0.

Expression Encoder : Silverlight Streaming Publishing Plugin for Expression Encoder 2 is out!