Indicthreads has an article about why they are not using a Java based CMS, but one made in PHP here.
I also chose a PHP based (WordPress) system for this blog, and have been looking into EZPublish lately. It’s really feature rich, and with it’s flexible object definitions through the web it seems usable for most scenarios.
The difference between the Java and PHP communities seems to be their focus. The Java community seems to have a great deal of focus on reusable APIs and backend software (Tomcat, Geronimo, Struts etc.) while the PHP community seems to be focused on more complete products (Mambo, Drupal, Gallery, Kplaylist). That’s why, when I need a complete product to avoid coding it myself I usually end up with PHP based solutions. This is probably already changing a bit inside the Java community and we are seeing more unpolished products like Magnolia, eXo and Liferay. As it matures I think they will be able to compete easily with PHP based solutions.