I don't even think they are popularization to be honest. As that would involve an effort to educate or inform about the state of the art. Neil deGrasse Tyson is an effective popularizer (but not a very good one); Richard Feynman excelled as a popularizer.
TEDx seems to be more about entertaining than informing a certain audience that attends because they want to feel part of the brand. It's like how Reader's Digest and Book-of-the-Month clubs formulated middlebrow culture and profited from middle class desire.
It could be argued that TEDx is the contemporary equivalent of salon culture that flourished in the 17th and 18th centuries. [0]
TEDx seems to be more about entertaining than informing a certain audience that attends because they want to feel part of the brand. It's like how Reader's Digest and Book-of-the-Month clubs formulated middlebrow culture and profited from middle class desire.
It could be argued that TEDx is the contemporary equivalent of salon culture that flourished in the 17th and 18th centuries. [0]
[0]: http://en.wikipedia.org/wiki/Salon_(gathering)