One of the nice things about Macs is the ability to drag and drop stuff anywhere and it just figures out what you meant. I use iMovie to create training videos of presentations at Yahoo. Part of that means overlaying slides on top of video.
The obvious thing to do would be to drop the Keynote presentation into iMovie. iMovie doesn’t like that. Instead you have to export the Keynote presentation as images and then drop those in. Not very intuitive. The most important thing for me, the thing that really makes you feel like everything is perfect with a computer is flawless work-flow. When I can switch from app to app without trouble I know things are right.
Apple’s drag and drop isn’t quite the Pipe of the GUI yet apparently.