After the update of Linux Mint 17.3, Clem as usual has named the next version and has counted some milestones that the new version will include. Linxu Mint 18, the next version of Linux Mint will be called Sarah, in honor of the biblical character and continuing with the names of women.
As announced several months ago, Linux Mint 18 will be based on Ubuntu 16.04, the next LTS version of Ubuntu and will continue to have the 18.X nomenclature until the next LTS version comes out. However, this will not be Sarah's main change but her interface and her look. As Clem has confirmed, Sarah will have the new version of Cinnamon, in this case the corresponding version 3.
Cinnamon 3 will mean a total change in the distribution
Cinnamon 3 will change many things, not only performance but also aesthetics and these changes will be present in Sarah. Also in the MATE part, Linux Mint 18 will also change, so the Linux Mint 18 Sarah MATE 1.14 will appear, in the next MATE 1.16 and so on. Clem has reported that they have a good relationship with the MATE development team and with each version of Linux Mint a new version of the popular desktop will appear.
Linux Mint KDE users will also be in luck as it will have the latest version of Plasma, a version that will already be included in Sarah and that will also change the look of the traditional KDE Edition. At the moment these are the changes that we know about. The XFCE edit looks like it won't have any changes and it is somewhat strange since it would be the only flavor of Linux Mint that does not receive changes.
Of course, Sarah will turn out to be an important milestone for the distribution but it must also be recognized that it will be a turning point that could cause Linux Mint to lose users. If the new Cinnamon changes do not like it, many users will abandon the distribution and also the desktop, something that could be negative for the distribution, even so, we will have to wait to see what Cinnamon 3 and Sarah will be like.