> That though doesn't bind prefixes, it just does away with the 
> need for prefixes altogether, so instead of
> 
> (:# xmlns:p=http://other/uri #:) /p:foo/p:bar[2]
> 
> you'd write
> 
> /{http://other/uri}foo/{http://other/uri}bar[2]
> 
> which is workable, but a bit long winded, especially in 
> attribute value templates, where { already has another 
> meaning, and so would need to be quoted.

I have considered this approach, which might be useful for handling
software-generated path expressions; but I think that use case is a lot less
common than XPath expressions written by humans using a text editor in some
kind of data file (or online form) where there's no obvious way to specify a
namespace context.

Michael Kay
http://www.saxonica.com/