The second section of the Openshot GUI is the preview window. As you click through the different sections of your presentation an image of whatever part you have selected appears in the preview window. The preview screen also allows for the live playback of what you have put together thus far. I had the video aspect of the preview window lock up on me a couple of times during my use with Openshot however clicking to a different part of the presentation and clicking back quickly got things back on track.
The final section of the Openshot GUI has three different tabs in it. The top most displays any media you may have imported to use in your presentation (movie clips, pictures, audio tracks, ect). Just below this tab is one that offers a variety of transition effects, there are around thirty to choose from so a good selection to say the least. The third and final tab is effects/overlays you can apply to videos and images, there are around thirty of these as well and they range from a black and white effect to a fun "wave" blur.
Openshot allows for the saving of project files while you are putting together a lengthy project and once you are done with your presentation Openshot supports the exporting to a variety of different media types, including avi, mp4, m4v, iPod, and many others (depending on what media libraries you have installed on your system).
Is Openshot perfect? No it is not, but then what piece of software is? All in all I think Openshot is a fantastic tool and as of Ubuntu 10.04 it will be included in the default repositories for the world's most popular desktop Linux distribution. Running a non-Ubuntu based Linux distro? Not a problem. So long as you have python 2.6 and all of Openshot's other dependencies installed on your system the Openshot developers have a created a very sleek python installer script that makes it as easy to install as running python setup.py install as super user.
Did I miss something you like about Openshot? Maybe there is something you don't like that I failed to mention? Or finally perhaps is there another Linux video editing tool I have yet to discover you would care to share a link to?