Not the cleanest code, and it can use some TLC, but this class libary and sample program allow you to manage your Silverlight Streaming assets through the WebDAV API. You can call simple methods instead of issuing web requests yourself, and it also handles subfolders and queueing of create and upload requests, which is critical when uploading a ton of files for a DeepZoom application.

If you're interested in helping with this project, please let me know. I think it's a great start and could be something really nice if I had more time to spend on it.

Download it here: http://www.bluerosegames.com/slsexplorer.zip