The Center for History and New Media has released Zotero 2.0. (Note: the Zotero site lists a beta version, 2.0b3.)
Characterized as a "major upgrade" the new release adds new synchronization, personal page, and public/private group features among other new capabilities.
Have you checked out Archivd? Personally, I’ve found its metadata extraction to be more useful for my research than Zotero’s.