I too was looking for a method in Javascript using the Tridion JS Framework to read an item or folder using WebDav. Without writing my own service that is...
Tridion 2011
I came close using the "$xml.loadXmlDocument" for an item and then creating my own request using "Sys.Net.WebRequest" for a folder.
Unfortunately, both are limited in data response, meaning you don't get item id or metadata.
I guess it's because they're using WebDav rather than a specific service.
Is it possible to use Core Services from Javascript, if it is then WebDav works fine in that API.
Thanks
Updated: Yes it is possible, but it's tricky. I created myself a prototype (customExecute) for Sys.Net.WebRequest to allow headers to be passed in, then set the content type to text/xml and a SOAPAction using the ICoreService format, the soap request was then passed as the body, once it complete I removed the namespaces and converted the content/metadata strings to elements... this worked well and allows access to CoreService generally from JS.