They have now launched TED-Ed, a new lesson-based YouTube channel. Aimed primarily at high-school students, it is meant for teachers to submit their best lessons, in a 10 minute or less video. TED will send a portable recording booth out to the teacher whose lessons where chosen. The lesson recordings are then animated and posted on TED-Ed.
Here's a video about TED-Ed
TEDed has a new url: ed.ted, and the new site allows teachers to create interactive quizzes about the videos. Teachers can track their students' performance on the quizzes also.
TED-Ed YouTube Channel: http://www.youtube.com/user/TEDEducation
TED-Ed Homepage: http://education.ted.com
Official TED App for Android now Available