This video interview clarifies several points about Google sitemaps, is there really a "Duplicate Content Penalty" or only a “Duplicate Content Filter” and what does that mean for webmasters. Many other issues regarding Google and SEO are also considered. The interview is conducted by Rand Fishkin, SEO expert from SEOmoz.org who interviews Vanessa Fox from Google.

Plan on spending about 17 minutes, but this is 17 minutes that are well spent. Much of this you may already guess, but there is some very good clarification on several matters regarding Google and SEO.