There's no uncertainty about this: The Fedora 20, "Heisenbug" beta release is here and is a fantastic sneak peek into the final Fedora 20 release. It's jam packed with fantastic free and open source software, lovingly configured and ready to use.
What is the Beta Release?
The beta release is the last important milestone before the release of Fedora 20. A Beta release is code-complete and bears a very strong resemblance to the third and final release. Only critical bug fixes will be pushed as updates up to the general release of Fedora 20. The final release of Fedora 20 is expected in early December.
We need your help to make Fedora 20 the best release yet, so please take some time to download and try out the beta and make sure the things that are important to you are working. If you find a bug, please report it – every bug you uncover is a chance to improve the experience for millions of Fedora users worldwide. Together, we can make Fedora 20 a rock-solid distribution. We have a culture of coordinating new features and pushing fixes upstream as much as feasible and your feedback will help improve not only Fedora but Linux and free software on the whole. (See the end of this announcement for more information on how to help.)
Since it's a beta release, some problems may still be lurking. A list of problems that we already know about can be found at the Common F20 bugs page, found at http://fedoraproject.org/wiki/Common_F20_bugs.