"Recording video is one of the great features of the iPhone and iPad, but before you send it out to a friend or upload to YouTube, you can make some quick edits and ditch unnecessary parts of any recorded video by using the built-in Trim feature. It's just like trimming in QuickTime but it can be done right on your iOS device: "
Screencasting software for desktop/laptops is fully developed** - users can record screens while opening and closing applications and have access to post production elements (titles, transitions, trimming, etc) all from within the software. iPad apps are not so fully developed yet - with iOS4, users can only record what is going on within the screencasting app.