Edit: I jumped the gun on this slightly and I apologize. These are the release candidate or RC versions that are available right now - or a Beta release in Windows terminology. The final release for end users is another 3-4 weeks away.
I know it's a Windows oriented forum here, but in case anyone is interested, Linux Mint 17 Qiana was released today. This is the long term release version and will be supported until May 2019. So far, only the Cinnamon and MATE desktops are available for download, the KDE and Xfce flavors will probably be along shortly.
Here is the link for Cinnamon: http://blog.linuxmint.com/?p=2615
And the link for MATE: http://blog.linuxmint.com/?p=2616