XJConfForPHP, the XML-to-object-mapper, Frank Kleine and me are working on is now available as a daily snapshot from snaps.php-tools.net.
While the project started as a 1:1 port of the Java version, we are constantly adding new features as well as unit tests. If you need a flexible solution to parse XML documents and create PHP data structures, you might give XJConfForPHP a try.