I thank everyone for their responses. Perhaps this bears out Dr. Kay's claim, but I'm actually more baffled than ever. If the NUnit test-results.xsd schema specifies *no* namespace, then the types it declares are in *no* namespace, is that right? How does a schema-aware parser use them, if at all? Does it simply fake it (i.e., if you were foolish enough to declare types in the non-namespace, I guess I'll have to bail you out)?
My more immediate question, which I might need to answer for myself, is simply, is NUnit's schema just "wrong"?