Right now my main interest with using blender is to use it with live action footage. This includes rotoscoping, mixing live action with 3D footage ( which in itself is a huge area to explore ) and also using the sequencer as non linear video editing system for my dv footage.
I am proud owner of a panasonic dv camcorder and looked for a reliable solution for video capturing, editing and dvd creation under linux. The process took quite some time and incorporated the evaluation of kino/dvgrab, kdenlive, qdvdauthor and of course blender.
Right now I use dvgrab for capturing the dv footage, blender for all the editing and conversion to a mpeg2 stream and qdvdauthor to actually master the dvd. I found blender to be extremely fast and capable of handling multi GB raw material, and once I had enough practice the editing process was very fast as well. The additional benefit of incorporationg simple rendered footage (e.g. Text) makes it a very versatile tool.
Today I discovered a new challenge at blenderartists.org, dealing with rotoscoping a lightsaber into live action footage. As I have played around with this just some weeks ago and came to a generic lightsaber node setup, I will maybe give this a try.