Quartz Composer seems to be forever quoted as being about to die but from what i see the re is a healthy Quartz Composer community that will continue using the software in innovative ways for a long time if/when Apple stops development.
To celebrate 10,000 downloads of the Quartz Patcheson my downloads page here is a pack of 34 .qtz files to play with.
Grab it on the downloads page.
http://destroythingsbeautiful.com/downloads/