Richer & richer semantics?

I think we all agree that enriched hyperlink semantics are A Good Thing...
the question is, what are the trade-offs?  It is a basic requirement that 
anything we put into this be (a) tractable to implement and (b) easy to 
explain.  It's not clear to me that a solution based on groves/grove-plans, 
or a query language, meets this requirement.  It's also not clear that it 
doesn't, but this is a challenge that must be answered.

One of the reasons that it must be answered is that a minimum solution,
essentially just making a formalism for multi-way typed hyperlinks, is 
dramatically more than what the Web guys have, and can be put *instantly* to
good use.  Thus if we do a good job on that, we have a good chance of buying
enough credibility to get some support to take us further down the path.  On
the other hand, if we produce something that is even one-tenth as difficult
to understand as, for example, the current HyTime standard, and does not
lend itself to instant implementations, nobody will notice or care.

Hell, I want general transclusion a la Xanadu...

Already, I think we've learned another chunk of Minimum Progress Required to
Declare Victory: 

 5. Minimum Progress on Extensibility

 The chosen mechanisms should have the property that they not impede 
 progress toward the addition of advanced hypermedia mechanisms up to
 and past general transclusion.

Cheers, T.