X-Plane 9.00 features 867 flight instruments, 25,737 airports, and 25,866 navigation aids. There are also major rendering and scenery improvements in this latest release. All of the details can be found on the X-Plane website. A demo version of X-Plane 9 is available, but the full version with the scenery will cost you. Laminar Research sells X-Plane 9 for $79 USD.
X-Plane 9 will soon be a staple to the OpenGL testing in the Phoronix Test Suite. Laminar Research is not only producing the PTS profile, but they will even be shipping a specialized (free) build of X-Plane 9.00 that is specifically designed for benchmarking within the Phoronix Test Suite with unneeded parts of the software being stripped out. Major props to them and their great work.