The Roy Rosenzweig Center for History and New Media has released the PressFoward plugin for WordPress.
Here's an excerpt from the announcement:
A tool for aggregating, curating and publishing content from the web, PressForward will change the way that websites find and publish the news and stories they share. PressForward enables individuals and communities to develop their own aggregated publications and will change the way that journalists, bloggers, and institutions find audiences for their work.
Available for download from the WordPress.org Directory or from the Administrative Dashboard within a WordPress website, PressForward allows users to collect content published elsewhere on the web, discuss it with potential collaborators, and format and publish that content without ever leaving their website dashboard. For those who want to roam the web looking for news or articles to share, PressForward also provides a bookmarklet that makes it possible to capture content for your website with a simple click on your toolbar.