Thanks (belatedly). Your post is one of the clearest I've read on this topic. I'm working on a presentation for budding young K-12 teachers, many of whom want to use YouTube and other Web 2.0+ in their classes. We're all trying to keep students engaged with media, use media when school networks aren't allowing full access, stay legal, etc. You will get a hat tip. Catch-22 for me is: Now I want to run the TED talk on short notice, so my presentation shouldn't be uploaded or streamed! (though I'm sure I can get permission from them later)