According to the WebDAV faq:
A final goal of DAV is to leverage the success of HTTP in being a standard access layer for a wide range of storage repositories -- HTTP gave them read access, while DAV gives them write access.
Dudes: OpenACS has allowed write access for some time now! All, or most files in OpenACS probably shouldn't be manipulated via WebDAV, since they need to be in CVS.
Locking
Locking? Hello! How do you plan on locking database content? Even if you can, why? Doesn't CVS already handle this situation, much better? BTW, this is the main point of WebDAV. For CR data, you have all revisions already. If two folks update, you can always choose another revision.
WebDAV is a protocol.
That means we still need an API to access OpenACS data. However, if you are going to construct an API, why not just do it in HTTP?
Minimum you need to be able to get?object=myobject&attribute=myattribute&id=123
Then similar procedures for update/delete.