Yes you have to remove the duplicated content or else it result in ban of your website. Always try to have fresh content which will increase traffic to your website as well as increase your page rank.
Yes remove that, and write unique content for your site or blog. after that update your site/blog in Google for cached new material...
After reading all the above posts... I am agree with you all that google or any other search engines don't like copied content... But when you have done a mistake, don't try to repeat it again..rather play safe. One great thing you can do, and which will save you from duplicacy.. Put the url just below the copied content from where you have taken them.. this will not get treated as copied...
Google didn't like copied content. Its also not good for SEO. Content should be unique because content is the most major part of every website.
Do not remove them. Google will see they are duplicate and will just not rank them very good. But the unique pages will get ranked good. Do not think about it too much. It is not like you will be penalized or banned or something. People have sites with tons of only duplicate pages and are doing well.
You should remove the copied content as no search engine will like this. Also the copied content when tracked by SE will surely ban your site. So its better to write unique quality content rather than to pay off by the search engines.