While this story is a bit old, some of you probably still don't know. Apple has changed the end user agreement in the server version of Leopard to state that it can now be run in a Virtual Machine. Being able to run multiple servers on one Xserve may also lead to companies choosing a real server machine over a Mac Pro with OS X Server installed. This also means that there could be a Xserve update soon. It takes a lot of horsepower to run multiple servers on one Xserve.