I could talk about the advantages of object databases for hours. Problem is, I really don't believe in them. With the advent of XML and Native XML datastores and DOM repositories, the usefulness of native C++ and Java OODBs is gone, unless you have extremely tight response tolerances in your software, such as cellular switching equipment. I've worked for eXcelon Corporation, formerly Object Design, now Progress Software for four years supporting Objectstore and XIS, a native XML data store. I'm confident that SQL will remain king of the data management world for quite some time, but I do see the hybrid tabular/XML database coming to the forefront over the next few years.