Maven 3 was release some time ago and besides being the latest stable release it is also a great improvement in terms of stability, bugfixes and code quality. This alone should be enough, but there is more to consider. With Maven 3, we also have a first (experimental) parallel build (see: https://cwiki.apache.org/MAVEN/parallel-builds-in-maven-3.html) feature included, that could potentially reduce the build times significantly.
Of course this is not something that comes for free. Roo also needs to support
ROO-163 and ROO-120 in order to take advantage of the parallel build feature. Even worse, not all plug-ins do yet support parallel builds (especially db, file handle, socket handling and alike is tricky here of course). However, enabling Roo to use the latest Maven version will be the first step on this way.
Although most of the Maven API stayed the same, there are some changes, especially in the area of dependency management. I guess this is the reason for the current problem when building with Maven 3. Here is the output I receive when building with Maven 3.0.0: