Hannahness - 6:20 am on Aug 23, 2010 (gmt 0)
"But now I'm reading some SEO blogs that warn against serving the canonical link on the "original" URL. How could that be a problem?"
I'm currently working on a site that has site-wide canonical link elements on all of the original pages. And it's not a tiny site - it's about 30k pages. Even dup content pages contain canonicals on their original pages. (Obviously I'm currently working to change this). From what I've seen, the vast majority of posts/articles crying out against the canonical link element aren't crying out against the canonical itself, but webmasters who don't understand how to implement it.