As you may know, Ubuntu 16.04 LTS will be still using Unity 7, the same desktop environment as the previous Ubuntu releases, but each Ubuntu release adds new DE changes. Unity 8 will be also available on the next LTS version of Ubuntu, but it will not be implemented by default due to the fact that its still under development.
According to Marco Trevisan, one of the Ubuntu developers, the unity 7 DE has received a new feature, permitting the users to rotate the Unity interface and move it from the left of the screen to the bottom. Marco has started the work at the Unity Shell rotate function in mid-September, but the update has been added to the Ubuntu repositories only now.
As a reminder, Unity 8 has been made available only on Ubuntu Touch, which is the mobile version of Ubuntu. The Canonical devs are currently working at porting both Unity 8 and Mir (Ubuntu’s new display server) to be used on Ubuntu Desktop, but they are not hurrying up with it, preferring to make them as stable/usable as possible, until they become default options.