So, you feeling OK about sending such a proposal to Google guys? They will forward to Apache people, so I will post proposal to derby-dev mailing list also for conversation in community

By the way - MySQL use special XML mode for client, where needed, http://dev.mysql.com/doc/refman/5.0/en/mysql-command-options.html#option_mysql_xml, instead of normal XML formatting:
<...>
 <VariableName>...</VariableName>
<Value>...</Value>
</....>

I see that like a big disadvantage because of inability of XML validation threw XMLSchema after retrieving on client

 http://java.sun.com/javase/6/docs/api/java/sql/SQLXML.html: there is something about XSLT, but that should not be a database feature, nor JDBC itself. It is pure client stuff (read: code, initiated database requests threw JDBC). John