When doing an Office 2007 installation - I noticed an installation folder with the mysterious name - Rosebud (I was pretty sure, it had nothing to do with Citizen Kane ...). After looking around a little bit I found some interesting comments on a posting by Scott Hanselman . Here is a quick rundown of the info about Rosebud:
Rosebud isn't new, actually I remember coding Exchange 2000 and SharePoint 2001 customisations using it around 6 years ago. As you correctly pointed out, it is the "codename" for the MSDAIPP component (Microsoft Data Access Internet Publishing Provider) an OLEDB provider for WebDAV, and it is used for client access to SharePoint. If you are really bored, this KB article talks about it all in more detail (2003 flavour of products) http://support.microsoft.com/?id=838028, things may have changed with the 2007 flavour.
And here is another one:
Rosebud (the ms data access internet publishing provider - msdaipp.dll) is not new - I wrote it in 1998 at MS. It is in fact an OLEDB provider that makes the Internet look like an OLE DB rowset. A row is an URL that represents a web resource (such as an html page), the columns of the row represent various properties of the resource such as size, mod date, etc. This page in turn may itself be viewed as a rowset which will be filled with all of the links on that page. In this way you can navigate the web by tunneling through rowsets. It supports FTP and HTTP protocols. It's smart about DAV if the server talks DAV. It even works with the local offline cache and will return resources from the cache if they exist there. Rosebud is the primary way that Office Web Folders and My Network Places get to the Internet, while being smart about offline files.
To use it just instantiate a provider with provider name = msdaipp.dso, data source=an url. More info at http://support.microsoft.com/kb/248501/.