Not exactly.
I am wondering if the document for WinJS.Binding.List is just not complete or if its dataSource property is somehow 'inherited' from something and that there is some way to discover it from the API documentation.
I see that in the VS debugger, I can drill down the prototype and find it, but it seems to me that it ought to be in the API document, no?
I left a comment on the API page. Maybe the owner can elaborate.