Googling for some insight on the SPDataSource I came across the blog by the guys at SharePoint Solutions.
Its a very usefull programming reference blog.
If you are a SharePoint developer check out their blog, because they have some good tips to share, and while the posts may not be many, the content so far is good.
Link: http://sharepointsolutions.blogspot.com/
tags: SharePoint, Development, Visual Studio 2005, WSS