Maven 2 has a dependency plugin, with a useful goal called "tree" (mvn dependency:tree). This shows the complete tree of dependencies Maven is evaluating for inclusion. It's useful for debugging when a transitive dependency gets included and you're not sure where it's coming from.
Will there be support for this in IDEA? Currently I have to return to the command line to look into dependency problems. Ideally (hehe) I'd like to see the dependency tree and select which transitive dependencies should be excluded in the POM.