I share alot of my articles as promotions for my gambling content site… and I use nearly all of the articles I find here, or submitted on my other website, if for no other reason then to help the folks writing for backlinks out. I also post a few press releases that interest me.
The result seems to be that these duplicate pages get a PR of about 2 most of the time, sometimes even 1. However, it doesnt seem to have any effect on the site as a whole.. just a lower PR for that one particular page.