I'm not sure that this approach addresses the need to have a standard
mechanism by which (server-side) XML documents are updated. We'd simply
be relegating the standard to being defined by OMG IDL interfaces, as is
done in DOM. We could rely on (future) DOM-defined query mechanisms,
except that the DOM approach does not provide the kind of flexibility
that an XML-based language would provide. For example, in the DOM
approach, our queries must be programs, whether they are written in Java,
C, C++, VB, or some script language. But then we'd wish we had defined
the script language. User's wouldn't have to learn a different language
for generating queries on each platform, and the queries themselves
would be transportable between platforms.