Nofollow tags - Google's Matt Cutt's Explains

Reprinted from Youtube.com

February 26, 2009, Google software engineer Matt Cutts collected questions on Google Moderator and answered many of them on video.

Vince Samios from the United Kingdom asked:

Do you feel that the widespread and blanket use of nofollow tags is devaluing Google's search algorithms? Examples such as Wikipedia, where ALL external links are nofollow. Does Wikipedia mean nothing to Google's algorithms?

jonaths from Brighton, UK asked:

Do Google take into account quality factors from nofollowed links when the links come from well established authority websites, such as Wikipedia?