Nuxeo is an open source ECM vendor that, thus far, has flown under the radar (at least my radar). They have a comprehensive package that includes document management, collaboration, digital asset management and more. One of the centerpieces of their system is the Nuxeo NewsWave rich content editorial system for press agencies. Watch for them in 2009. Website [1]
Links:
[1] http://www.nuxeo.com/en/