"I think I’ve got good news for everybody. We decided to join the new trend and jump on the bandwagon (as people say) with a new “flat” theme called “Mint-Y”, based on the very popular “Arc” and “Moka” themes. But, we also decided not to be bold and so rather than a brutal change we’ll be introducing this new theme slowly and supporting both the old “Mint-X” and the new “Mint-Y”."...Clement Lefebvre
Note: The BETA release for Linux Mint 18 is expected in June. No particular dates will be given and the ISOs will come out “when ready”.