Standard means to convert text to XML?

[Brett Zamir <brettz9@yahoo.com>]

Hello,

With all of the many and great tools for handling XML--XSLT, XQuery, 
etc., I was wondering whether there were any W3C-standard means (or 
plans for such means), to take a text document, attach a "schema" to it 
in some manner (externally or with some code at the top) and then parse 
the code according to rules defined in the schema into an XML (or 
possibly other) language?

While it is great to be able to transparently handle conversion FROM 
XML, it'd be nice to be able to transparently convert non-XML INTO XML 
(which could ideally use the same schema to round-trip back into the 
original)...

thanks,
Brett