definately! its not that much.
you can save QuickTime audio or video from a webpage, copy and paste audio and video so its like a mini movie editor, record video with iSight (although Photo Booth in Leopard now does this), create slideshows and export video, audio to different formats.
so if you converted a DVD to mp4 using Handbrake for you iPod but then wanted to make it even smaller to share with someone you could export it as a QuickTime movie with a lower resolution and frame rate to get the size down.