Just a few quick updates:
1) Looks like the Castor article is going to a webzine rather than the website. I'll let you know...
2) Made some progress on PUNT, which is a set of filters for converting Namespace prefixes in XML to encoded URIs. Results in real ugly documents, but it may be a useful tool for those still operating in namespace-unaware environs (or where namespaces are just handled badly by some third-party joker who won't listen to you).
3) Thinking more about a typed metalanguage (TML) that is backwards compatible with XML. I've had a couple of interesting debates with people on xml-dev of late.
For instance, Simon St. Laurent's a big fan of loose constraints, lexically specified, whereas I'm more the semanticly-undestood datatypes advocate. The twain have to meet somewhere, though. Further exploration of the TML concept should help delineate those boundaries. The XML Schema datatypes guys have pointed the way, although they got lost somewhere on the trail, probably attributable to politics and compromise (and deadline pressure).
There's something to be said for being a cowboy.