I'd like to add that there's a handy plugin for Azureus named AZCVS Updater which automatically downloads and inserts the latest CVS files (Azureus Jar Core). Latest CVS is currently the 3.0.0.5_B2 build.
It's nice to see how Azureus is developing using this plugin (every two days, sometimes even twice a day, a new CVS will be released), and you can test the latest features months before everyone else
That said they are just snapshot... they may crash or produce other unexpected behaivour, though, this has yet to happen to me.