I've wanted this for quite some time. Nice work Stefan!
The fact that we've all been forking a brand new JVM for each JUnit test case in hindsight is quite insane - surely we've far better things to do with our time than wait & watch JUnit output slowly trickle down a page :). (Admittedly starting up a new JVM seems fairly snappy on OS X, though still, starting a new JVM on 1.4 isn't cheap).
So all we need now is the maven plugin to add support to this & we can start using it on all the projects I work on...