The W3C XML Core Working Group
has posted a proposed edited recommendation
of Associating Style Sheets with XML
Documents 1.0, i.e. the
"This second edition incorporates all known errata as of the
publication date, clarifies several areas left unspecified
in the earlier edition, and has been restructured to allow
other specifications to reuse the rules for parsing
pseudo-attributes from a string. This edition, once it
becomes a Recommendation, will supersede the previous edition
of 29 June 1999."
After a quick read, this looks like an improvement over the existing spec though a lot of details are still left unsaid.