Only (certified) feature is present but underlying PMD feature which is missing. So installation goes ok but no PMD is installed.
Update site: http://www.qa.jboss.com/binaries/RHDS/updates/development/4.1.0.CR3_extras/
I set it as a blocker, but if decided PMD must not be part of JBDS 4.1 update site (then lower priority).