Content duplication has been a buzz topic in SEO for a while now. There is still the lingering perception that there is some sort of duplicate content penalty despite repeated assurances from multiple Googlers to the contrary. Penalty or not, it is clearly the case that the site where content originates may not always rank best for that content.  Google wants to do their best to make sure they keep the content of their results pages as distinct from one another as they can.
http://www.webpronews.com/topnews/2009/12/30/content-syndication-is-your-friend