Hi Steve,
What is the exact purpose for that?
There is no such feature yet because to tell if an object is changed is complex conceptually: does it concern only to scalar properties? What if a property of an associated object is also changed? Does that mean parent object is considered changed - a Flush(Parent) will fire updates in database in this case. What about collections? Should it check for added/removed items?
You can use ObjectChanged if it fits your needs - although that's not exactly the function the manager uses. The reason why the order is important is because of proxies: an unloaded proxy means that property is untouched. So if the "DirtyObj" has an unloaded proxy it means it's not changed, regardless of what OriginalObj contains.