Matt Cutts is getting in the habit of posting helpful videos along with accompanying slideshows. He has continued this tradition today with one of each on the recently announced Canonical Link element introduced jointly among Google, Yahoo, and Microsoft (Cutts notes that Ask has gotten on board as well).
The video is 20 minutes long, but interesting nonetheless, and is something webmasters should pay attention to. It comes with captions too, and the slides are quite useful.
As Matt mentions, webproworld conducted an interview with him just as the canonical tag was announced. You can view that here:
More webproworld Videos
I should point out that webproworld has a YouTube channel that features videos related to Google’s Webmaster Central.