as seen on gnome-list, what's new includes "multiple documents interface, with copy/paste and drag'n'drop; multiple selections (useful with LyX citation for example); all the supported formats (bibtex, medline, ovid, refer) can now be read and written; better date handling; bug fixes." for more see the pybliographer download page at gnome.org. if you haven't tried this yet give it a shot; i might finally get rid of endnote + msword (and there was much rejoicing). :)
seen on many lists recently is XMLMARC, a "Java client/server program [which] converts MARC to XML based on flexible maps and simplified, yet detailed DTDs for bibliographic and authorities formats." Its license is free for non-commercial use but requires consent for redistribution, and their broader experiment is described here. They seem to be aware of MARC.pm... it would be great to see a side-by-side feature comparison of the two.