Ad-hoc XML databases with MySQL 5.1

When I saw that Kimbro Staken was part of the Structured Blogging team, I hoped that this meant the structured data chunk would be more than just XHTML markup and become a proper alternative to using a dedicated XML database. Now that MySQL 5.1 will include the long-awaited ability to do XPath queries and manipulations, this looks like it could be close to reality (this addition to MySQL should also be good news for Atom stores in MySQL and makes all microformat markup much more useful).