[XML Schema 1.1] Is the Conditional Inclusion (VC) stuff useful today?

Hi Folks,

I'm having a hard time seeing the usefulness of vc:typeAvailable, vc:typeUnavailable, vc:facetAvailable, vc:facetUnavailable, vc:minVersion, and vc:maxVersion.

I can see its usefulness in future versions of XML Schema (version 1.2, 1.3. etc) but I can't see its usefulness today. 

Does it have any usefulness today? If so, can you give me a practical example please?

/Roger