My guess is that this is the common feeling for anyone very familiar with the material of a TED talk. However, it does spread ideas and make them available to others that would not have otherwise encountered them. There is incredible good in that.
At the end, Garber talks about how information should be a public concept. I suppose Wikipedia would perfectly encapsulate this idea. It allows people all over the world to contribute knowledge to any topic without claiming ownership of ideas. To that end, I see no reason why TED and Wikipedia can't coexist.
I use it every day. It is an incredible font of knowledge. It is such a great thing that Jimmy Wales had a vision for it. I hope groundwork is being laid to keep it in the public sphere for a long time to come.