The features of Unity combine both MacOS and Windows 7 user interface-like layout. There's a vertical task management panel dubbed "the launcher" that's similar to the MacOS dock. The application iconography represents applications, but not instances of the applications (which are re-instantiated along the launcher in a list).
Unity also searches and finds files and internal data quickly, and worked with many applications — the default launcher supports the recently updated LibreOffice suite — but the menu bar does not.
There is also a global menu bar very similar to MacOS global menu bar placed across the top of the screen area. Its context will change depending on what app we used.
We also saw non-production (the dreaded "advanced look") primitives for Unity-based touch pad controls, including multi-touch — which seems poised towards a pad or tablet device. We can't comment on its potential usefulness, only its potential competitiveness. The Unity 3D user interface is most preferred, and in future editions might give Apple a run for its user interface money. Full Linux with Unity on an advanced tablet might give Android a competitor, too.
As LibreOffice 3.3.2 is included as the default "office app suite," Ubuntu changed a few accessory components, as well. RhythmBox has been replaced by Banshee. Firefox 4.0 is included. All of these work with Unity's window arrangement, except as noted.
Server, cloud and images
The server editions include many components that poise Ubuntu Server towards cloud environments, largely blurring server differentiations into cloud and VM use profiles. Ubuntu Server focuses on multiple instance deployment, use, and management as a virtual machine, or member of a larger set of server instances.
After we downloaded our review copies of Ubuntu Server and Enterprise Cloud versions of 11.04, Canonical announced that it's going to move away from its primary cloud management toolkit, OpenEucalyptus, which we enjoyed using in our first look in Ubuntu Enterprise Cloud (UEC) in the Ubuntu 10.04 release.
OpenStack, a collection of applications we've seen before, will be the direction that Ubuntu supports in the future. We had decided difficulties with the Eucalyptus commercial versions for cloud control and openEucalyptus will continue to be supported while OpenStack is ramped up.