The Center for History and New Media at George Mason University has released Omeka 0.10b.
Here's an excerpt from the announcement:
Omeka 0.10b incorporates many of the changes you asked for: an unqualified Dublin Core metadata schema and fully extensible element sets to accommodate interoperability with digital repository software and collections management systems; elegant reworkings of our theme API and plugin API to make add-on development more intuitive and more powerful; a new, even more user friendly look for the administrative interface; and a new and improved Exhibit Builder. While the changes are extensive and represent a next-to-last step forward toward a 1.0 release in early 2009, existing users of Omeka should have little trouble switching to 0.10b. New users should have even less trouble getting started. Meanwhile, visitors to Omeka.org will find a new look, a more intuitive information architecture, easily browsable themes and plugins directories, improved documentation and user support, and new ways to get involved in the Omeka community.