From Fedora Project Wiki
Fedora 21 Beta Release Announcement
The Fedora 21 beta release is here, and - as usual - is packed with amazing improvements to Fedora, as well as fantastic free and open source software, gently harvested for your enjoyment. No bits were harmed in the making of this beta.
What is the Beta Release?
Highlights in the Beta Release
A Note on Shellshocked
You've probably read all about the "Shellshocked" vulnerability in GNU Bash, which affected Fedora 19, 20, and 21 alpha. Rest assured that Fedora 21 beta has been patched to close this vulnerability.