Are you looking for Project Server 2010 Public Beta? Check out the links below.
Microsoft is also allowing you to access Project Server 2010 on their Hosted Virtual Lab – check it out. I believe it times you out after 90 minutes (at which point you can log back in). None of your data and/or changes are saved. This is for a test-drive only – not to be used for demo environments.
If you need a hosted environment for a Proof of Concept, Pilot, or Test area – let MS PROJECT NOW! know and we can help you out.
Demo Image (based on the Public Beta) if you want to test out Project Server 2010: