As the canonical Maven book suggests, you should use $[foo.bar.version} property expressions when you have multiple, related artifacts with the same version. Then you are able to upgrade all the dependencies consistently with minimal effort.
The NetBeans IDE 6.7 supports this pattern in the Add Dependency dialog. You can invoke that dialog from the Add Dependency action on project's Libraries node in Projects view, or from the pom.xml editor via Insert Code (Alt-Insert) editor action.
The Version field completion includes all *.version properties defined in the project (or any of the parent) and offers them as expressions in form ${*.properties}

That way you can keep your dependencies in sync right from the NetBeans UI.
In future 6.8, we also replace the GroupId and Version values with ${project.groupId} and ${project.version} if both the groupid and version match those of the current project. Again, a practise suggested by the Maven book.

Great tip! It is great to see tighter integration between NetBeans and Maven. Keep up the good work.