Naming suggestions are now open for Fedora 19, which is scheduled to be released sometime next year. The upcoming release, Fedora 18 Beefy Miracle is going to release end November 2012. Fedora maintains a 6 month release cycle while older releases get unsupported after a period of 1.5 years.
You can suggest your names at this wiki page. A good number of interesting names have already been suggested, like Crop Circle, Elastic Horses and Conical Frustum. Your name will be disqualified if its a trademark or the name of a living person. Also, there must be some link between your name and the name of previous release, e.g. Beefy Miracle.