Due out real soon will be the Linux Mint 17 "Qiana" release, which in turn is based upon Ubuntu 14.04 LTS. Succeeding Linux Mint will now be 17.1, 17.2, etc. Rather than basing it off of the latest six-month Ubuntu Linux release, Linux Mint developers will be sticking to a Ubuntu 14.04 LTS base until the unveiling of Ubuntu 16.04 LTS in two years. In total there will be three Linux Mint releases built upon the Ubuntu 14.04 "Trusty Tahr" packages with sticking to a six-month release cadence.
By sticking to the Ubuntu LTS releases that happen every two years, it will be easier for Mint users to upgrade between interim releases and will free up resources for Linux Mint developers to focus more time on playing around with Cinnamon and their other custom-written components rather than dealing with the constant flow of new Ubuntu packages and tackling those changes and regressions.
Linux Mint 17 will be supported through 2019 while it will receive new features and backports until 2016. For those Linux Mint users out there, the developers do intend to backport important applications and other pieces of software to their Ubuntu "Trusty Tahr" LTS base. A Linux Mint 17 release candidate is expected in the next day or so.
More details on these latest Linux Mint changes can be found via the Linux Mint blog.