I have 2 sites with the same subject matter that have been hit "mildly" by Penguin.
All the affected pages are toast, but when I create new content it still ranks pretty well.
So the sites are not totally hopeless.
One of the sites has a pagerank of 4 although the domain name doesn't fit my needs anymore.
The other site has a much better brandable name and PR3.
Would it be a good idea to redirect the site with PR4 to the one PR3 and shut down the PR4 URL?