o a test which demonstrates the difficulting in testing the execution of a single mojo, indicates some work to isolate the system and make it easier for people to reuse this code. igor had to jump through these same hoops to get isolated mojo execution working in m2e. needs some love.
maven/components/branches/MNG-2766/maven-core/src/main/java/org/apache/maven/execution/MavenSession.java
maven/components/branches/MNG-2766/maven-core/src/test/java/org/apache/maven/lifecycle/