While I have been using blender here and there for a few years now, the Video Sequence Editor (VSE) in Blender isn't something that I have used often, but I will say that it's not too shabby. It can deal with a decent variety of formats, and when it comes to chopping and slicing video up, it works fine. I don't know that it can demux/mux audio and video together yet, though. You also get a great node based compositing system tossed in for free.
That being, Blender seems to have a very strong community behind it, which is always a good sign of health for any OSS project. Plus you can't beat the price (free! \o/) or the ungodly number of tutorials for it out there.
Well, maybe I am just a tad bias...
Yours truly,
THE blender.org administrator
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