Duplicated content is bad, specially when speaking about google's policies. This is why at www.e-articles.info we only accept absolutely unique-content article submissions, meaning that no part of text is already published on the internet at the moment of the publication. It is really worth to have this guideline in the submission policy if you have a new article website and you don't want it to be penalized.
webstuffscan may have it right. don't just have duplicate content on your site. keep in mind that many newspaper and media outlets run the exact same wire stories on their sites and best i can tell they do so without an overall site-wide penalty. the duped stories may never show up in the searches but the site will still rank high provided there is some ratio of uniqueness.
I totally disagree with you, i manage 6 article directories, some very successful, and maybe 80% of the site content is duplicate content and i have had no penalties
The whole treatment of duplicate content should be reconsidered. Imagine someone stealing your content and then ranking higher for keywords with your stolen content than you are. This is happening to me at the moment with one of my (authoritative) websites. Guy in China rips my entire site with content and puts it on a brandnew domain and Google lists him higher for some keywords than my own website. Christoph
i do not condone people taking content without the owners permission but when you are taking about "article directories", their main purpose is to provide webmaster etc with content to use, free of charge.