Well, as a hack you could create a pom that just references the one on the central. But there would be two artifact – the vaadin add-on, and the core component.
If you want to see a pom that creates a Vaadin-compliant jar, javadoc and sources, you can look at code.google.com/p/criteriacontainer (I manually zip the three together and push them as a bundle, alternately I can send just the jar)