The Maven team is pleased to announce the PMD plugin 1.1 release!

http://maven.apache.org/reference/plugins/pmd

The Maven PMD plugin is a plugin that wraps the PMD framework
(http://pmd.sourceforge.net). PMD is a source checking framework that
works by scanning Java source code and looks for potential problems 
like: unused local variables, empty catch blocks, unused parameters, 
empty 'if' statements, etc.

Changes in this version:

o Adding maven.pmd.includes and maven.pmd.excludes to match functionality 
  in checkstyle plugin.
o Now respects pom.build.sourceModifications.
o Add xml declaration to generated report. Fixed for character encoding.
o Make sure the report does not fail if PMD does not detect any 
  violation. Fixes bug MAVEN-538

Note that this plugin has been tested with Maven beta 10. Using it with
another version of Maven is at your own risks! :-)

You can download the PMD Maven plugin here:
http://www.ibiblio.org/maven/maven/plugins/maven-pmd-plugin-1.1.jar

Have fun!
-Vincent