Ubuntu's Unity has hit the version 5.0 and is now available for testing in Ubuntu 12.04, the LTS version of Ubuntu slated for April release. Since 12.04 is an LTS version we can be rest assured that it will be extremely stable and perfect fit for those who skipped the 11x series due to Unity and other issues. With 12.04 users may also get the capability to disable the infamous Global Menus. If you are a daredevil and running Ubuntu 12.04 you can test Unity 5.0, rest can either wait of install Ubuntu 12.04 in a virtualbox.

How To Install Unity 5.0?
To install Unity 5.0 to 12.04 you need to add this ppa.
sudo apt-add-repository ppa:unity-team/ppa

Then update the system
sudo apt-get update

and then run upgrade
sudo apt-get upgrade

You should be running Unity 5.0.