With Maven 3.1.0, Sonatype Aether has been replaced with Eclipse Aether. m2e 1.5.0 will soon do the same. Currently, I've found that at least the following plugins have a dependency to the Sonatype version :

• org.jboss.tools.arquillian.core
• org.jboss.tools.maven.project.examples
• org.jboss.tools.maven.ui

Ideally the next m2e version won't embed the jars directly (but this is not guaranteed). Aether is available from this p2 repo : http://download.eclipse.org/aether/aether-core/milestones