Scientists and scholars who publish research papers in refereed journals and who submit research proposals to national and international donor agencies find commercial products such as EndNote, ProCite and Research Manager (all three of them sold by Thomson Group which also publishes Web of Science and Current Contents) very useful.
I do not know of any open source product which can perform the same functions.
http://bibliographic.openoffice.org/biblio-sw.html lists a few. But you're right. Commercial bibliographic management software may have more functions than others. So I guess it depends on what one wants. All the scientists and researchers I know use LaTeX/BibTeX and I haven't heard any complaints. Has anybody tried PKP's Research Support Tool? http://www.pkp.ubc.ca/demos/rsttour/ While not a bibliographic management tool per se, it appears to have some interesting features adding value to OAA. Hope this helps. Anita