It is currently hard to use IDE Libraries with distributed projects, yet it would be nice to be able to use the libraries ideas except stored within projects because they allow multiple jars, sources, and javadocs to be associated with a single unit. Something like Hibernate is a perfect example of a large multi-jar library. If these could be stored within the project it would make life much simpler, especially considering one project may be using a different version of the library than other projects using "the library" and it just makes it easier to add libraries to projects without getting resolve references issues where manual process is needed by all on a development team.
The idea is for Project Level Libraries to
Apparently there was already an open RFE for this and it has been started by Jesse Glick as issue number 44035.