I’m slightly surprised, but both Google and Yahoo decided to tell webmasters how they can prevent onsite duplicate content issues. Both sites published the posts about 15 minutes apart; perhaps this was discussed at SMX.
From Yahoo! search blog:
To do this, specify a <link> tag in the <head> section of your page content:
<link rel=”canonical” href=”http://example.com/products” />
The above tag indicates to the crawler that the URL it is present on should be represented canonically as http://www.example.com/products. This would eliminate the following duplicates:
I don’t think is necessarily a bad idea, but it just shows you how they are not confident in their own algorithms at detecting which are the authority-pages on your site.
PS: This could be a quick way to boost any pages that you want higher in the SERPs. Imagine taking all of my category pages of this blog, and directing them all to each of their corresponding top articles. I may test this out; it would just be a shame if I got this white hat blog penalized.