Cinnamon is a desktop environment built by the Linux Mint team and it's implemented by default in the Mint OSes. The current update, 2.4.7 is just a maintenance one, but it's pretty extensive and it comes with a ton of changes. Numerous updates have been released in the 2.4.x branch of Cinnamon, and it looks like the developers are not done with it, not by a long shot. They have already detailed 2.6.x, but it looks like that version is still pretty far away. In the meantime, users will be able to update their current Cinnamon version to a newer one that should provide a much better experience.