If you're going to bet your business or job on a development project, you want to be in control of the foundations - i.e. the build system. With Maven, you are not in control. It is declarative and opaque. The maven-framework developers have no idea how to build a transparent or intuitive system and this is clear from the log output and the documentation.
The dependency management is very tempting since it could same you some time at project inception but be warned, it is fundamentally broken and will eventually cause you a lot of headaches. When two dependencies have incompatible transient dependencies you will be blocked by a rat's nest of complexity that will break the build for your entire team and block development for days. The build process with Maven is also notoriously inconsistent for different developers in your team due to inconsistent states of their local repositories. Depending on when a developer created their environment, or what other projects they're working on, they will have different results. You'll find that you're deleting your entire local repository and having Maven re-download jars far more often than the first time setup for a dev branch. I believe OSGI is an initiative that is attempting to fix this fundamental problem. I would say that perhaps if something needs to be so complex, the fundamental premise is wrong.
I've been a maven user/victim for over 5 years now and I have to say that it will save you far more time to just check your dependencies into your source repository and write nice and simple ant tasks. With ant, you know EXACTLY what your build system is doing.
I've experienced many, many lost man weeks of time at several different companies due to Maven problems.
I've recently tried to bring an old GWT/Maven/Eclipse project back to life and 2 weeks of all my spare time later, I still can't get it to build consistently. It's time to cut my losses and develop using ant / eclipse me thinks...
