It seems to have two main basic "views". One view represents the default package manager GUI with software categories to the left and more information to the right side. But the other view, which seems to follow the Ubuntu software center GUI "patterns", has an enhanced graphical representation (using a lot of beautiful looking icons and all that stuff :D ) which does the same thing + I think this second GUI is more user friendlier than the other GUI.
As with Ubuntu software center, once you click on an application icon, then you're taken into a more in-depth view which contains user ratings, total space needed, a small introduction of the app that you selected, etc. And with KDE4... the KDE desktop has been simplified when comparing to the "daunting" amount of features that earlier versions came with. The Muon package manager also seems to inherit those attributes and certainly looks very user friendly, as mentioned above.
Although it's still at its beta stage, still if you use Kubuntu 11.04 Natty Narwhal, you can install Muon by using their official PPA channel. To do that, open your Terminal and issue the below command.
sudo add-apt-repository ppa:echidnaman/qapt-experimental
sudo apt-get update
sudo apt-get install muon