I am not a big fan of JDeveloper, or many of Oracle’s other tools and applications. I think they do databases really well, and the other stuff should be left to the people that originally started the project (Orion application server, Stellent UCM, WebLogic application server, Java, etc).
The free and popular Eclipse IDE can use one of the following two plugins that provide Maven 2 integration:
Maven Integration for Eclipse
Both have their strengths and weaknesses. Both do well with dependency management and POM validation, and both have a POM editor which is both nice to have, and annoying at times.