Xavier Le Vourch has released PMD 4.1! PMD is a Java static code analysis utility - it finds unused code, design issues, duplicated code, and much more. I posted earlier about the release candidate, and the 4.1 final is pretty much the same code - 14 new rules, a bunch of bug fixes, fewer false positives, and the IntelliJ IDEA integration works again. You can download this release or view the changelog.
On the CPD (copy/pasted code detector) side of the house there's better Ruby support and a new Microsoft Visual Studio output format. I used the Ruby CPD checker to scan a Rails app just yesterday and it worked great - it found a couple of duplicated methods across some helpers and controllers. You can even check .rhtml files using the "Any language" support and find duplicated code there.
PMD continues to develop nicely; I hope to post on the type resolution inner workings soon. Go PMD! And of course, go PMD book! Now a mere $20.