David,
Very nice article - it's one of the biggest debates we have here at work. Entity Objects, Business Object, How to do a DAL, How not to do a DAL...
All nothing but fun!
Remember a while back at the C# Study Group you presented Object Spaces? You once mentioned that there was a website with a tool to assist you in mapping the objects - you remember the site?
I hope Object Spaces comes real soon - this will take care of a lot these issues.
p.s. We have to get together sometime soon, again. Maybe breakfast with the wives some time.