If I have two sites in the same niche and site A does very well, has obtained a PR4 ranking on the home page and many inner pages. Site B gets very little traffic, makes about $4 per month and is ranked PR0 (I know PR isn't what it used to be, but I am just showing the difference between the two).
I would like to take the posts off site B and add them to site A and let site B expire (it is up for renewal this week). Would this be considered duplicate content since it was on site B for a couple of years, but now it is on site A? But site B will no longer exist.