Google put a great post up (video and
slideshow too) about how Google handles
duplicate content and multiple site issues.
I’ve always told my clients that Google doesn’t penalize sites and site owners for duplicate content. They just concentrate more on relevance and distinction.
As long as duplicate is legitimate and not
spam (intentional manipulation) it’s valid for
Google Search.
There’s a definite difference between penalties and site
SEO. Duplicate content, link dilution and
URL structures don’t necessarily make for good SEO.
Also, another misconception. Multiple domains hurt sites. Wrong. multiple domains are great SEO. If correctly managed.
What does Google

think of Duplicate content and multiple sites? (video) | TechBurgh Blog and PodCast