It's true, the null object pattern is awesome, it really is a shame it didn't make it into Design Patterns.
Null references are bad.
On a related topic, I haven't had a close look at C# v2 yet, but I think they have support for TVL. I think that's a bad idea, I think imperative code should not have logic necessary for set operations. But, what would I know.. :P
I wrote my own nullable type library, and it is little more than a uniform interface for querying for null and retrieving a value. You never operate on a nullable type, you operate on it's value, and it is an error to try and read the value of a null value, so you have to query IsNull first or you are implicitly asserting that the value is not null.
John.