Hi Jukka, I think an active Object to Content mapping subproject in Jackrabbit would be a great addition, since this really builds the bridge between the Java Developer and JCR, basically in a similar way how something like Hibernate or JDO makes JDBC development faster, simpler and more reliable. I think that a general purpose Content Repository project like Jackrabbit is an ideal place to host such a tool set.
Of course there are many reasons why a Content Repository, for example with its inheritance based node typing is much more adequate to handle POJO persistence than an RDBMS. I would be very excited and already "dream" of java annotation based content mapping and possibly node type definition in my java source ;) regards, david