Update:- Final version of Ubuntu 12.04 LTS has been released.
The countdown to another LTS release of Ubuntu has begun. Ubuntu 12.04 Beta 1 has been released for user to try out. The 12.04 version is named Precise Pangolin.The changes include the changing of default music player. Rythmbox is the default music player in ubuntu12.04.
A new feature called HUD is implemented through which users can quickly search for desktop applications by pressing the Alt key.
LibreOffice has been upadated to 3.5 beta 2.
You can download the beta version from here.
For further details go here.
Below is a screenshot of shortcut keys for ubuntu posted from OMG.