The preview of the Expression Encoder Publishing Plug-in for Silverlight Streaming is now available for download.
Download
This post provides the steps for:
It is a straightforward process that illustrates the software (Expression Encoder) plus service (Silverlight Streaming by Windows Live) integration.
SETUP:
1 - Install - Expression Encoder RTW version
http://www.microsoft.com/expression/products/download.aspx?key=encoder
2 - Install - Expression Encoder Publishing Plug-in for Silverlight Streaming
http://www.microsoft.com/downloads/details.aspx?FamilyID=382a3306-b212-4df3-af86-5d48be550b94&displaylang=en
3 - Sign up for a Silverlight Streaming by Windows Live Account if you don't already have one
http://silverlight.live.com
NOTE:
If you are unfamiliar with Expression Encoder, please watch the free training videos on using Expression Encoder. The Intro video is twelve minutes long and after watching it you can easily complete the following steps.
http://www.microsoft.com/expression/kc/resources.aspx?product=encoder&type=video
IN EXPRESSION ENCODER:
1 - File/Import a video (QuickTime, AVI, WMV, …)
NOTE: To save time, import a WMV file and choose SOURCE as the encoding profile

2 - If you are using WMV + Source Profile, you can add metadata and choose a Silverlight Player Template without having to re-encode and recompress your video. If you add a leading or trailing clip you will force a re-encode of the video.
3 - In the Output Tab/Job Output select a Silverlight Template (e.g. "Console")

4 - Encode the file
In the Output Tab of Expression Encoder, below the Job Output section there is a new set of Options titled: PUBLISH (If you do not see this, it means the Expression Encoder Publishing Plug-in for Silverlight Streaming Plug-in is not installed).
5 - Select Publish To: Silverlight Streaming

6 - You will see something like the following:

7 - Enter Your Silverlight Streaming Account ID and KEY
8 - Check Automatic Name or provide a name that doesn't already exist in your Silverlight Streaming account list of applications. If you choose your own name make sure the name is alphanumeric and has no spaces. Automatic Name is safest in that respect.
NOTE: If you have encoded a project during the current use of the xEncoder application, the Publish button will be active.
9 - Click PUBLISH
Once publishing is complete, you will get additional UI that provides the iframe code you can paste in to your web page, you blog, or whatever web application that supports iframes, where you would like to expose that video.
You can also see previously published applications from your Silverlight Streaming account as the Preview window is hosting the browser in its window. You can play the video directly from the Preview window.

Additionally you can delete applications directly from within the plug-in.
10 - Now your video application is hosted on the Silverlight Streaming service. You can login to your Silverlight Streaming account on http://silverlight.live.com and preview the app from a test page on your SLS account, or delete it directly from the Silverlight Streaming admin site.