Good news, Roo is maven-based. Which means that when you create a Roo project, you are creating a Maven project.
Roo supports maven in several ways.
First, you can define dependencies and plugins, and they'll interoperate with Roo. Generally you have a Spring project and you can add any dependency that makes sense.
Second, if you create Roo modules, you're making the top level project a POM, and then creating WAR or JAR modules below it. Roo will allow you to set the module focus so you're working on the correct one.
I understand there are still some issues with Maven parent POMs and the like. Maybe Roo 1.2.2 (just released) solves some of them. But basically if you use Roo you'll be building a Roo project with Maven.