In the nightly build of netbeans there is a module that can be installed called “Extra Update Center Module”. This can be made available in Netbeans 6 beta 2 by going to Tools–>Plugins–>Settings and clicking the “add” button. Then use the following url:

http://deadlock.netbeans.org/hudson/job/javadoc-nbms/lastSuccessfulBuild/artifact/nbbuild/nbms/updates.xml.gz

Click “ok” and you should now have access to the “Extra Update Center Module”. Of course the plugins that are provided by this module could be unstable. That is why it is only included with the nightly builds.