Dru Devore has a blog entry on java.net showing how to use an ANT based build with Maven and Netbeans to use the jar repository feature with Netbeans 5.0. Devore mentions that there currently is not build in Maven integration for Netbeans, but there are other plugin projects out there, namely MevenIde.
The comments to the post are interesting, because there are multiple posts from other people suggesting to look at Ivy, a jar dependency manager. I haven’t come across this tools before, so will take a look when I get time. Their project page is at: jayasoft.org/ivy