After pulling the plug on its CMS step-company, Astoria, Xerox has put renewed energy into its DM capabilities, which now rival those of Stellent (the former Web DM upstart), at least in breadth. The latest version of DocuShare (v3.0) is completely Web-based, for users and administrators. It's not a long jump from here to more unstructured content management. And a very low price point is going to put a lot of pressure on competitors, especially Microsoft's SharePoint server. BTW, in case you haven't noticed, WebDAV support has quietly become nearly ubiquitous...
Read up on DocuShare