The maven team is pleased to announce the Maven Source Plugin 1.1 release! 

http://maven.apache.org/maven-1.x/reference/plugins/source/

Java source archive plugin for Maven 

Changes in this version include: 

To automatically install the plugin, type the following on a single line:

maven plugin:download 
  -DgroupId=maven 
  -DartifactId=maven-source-plugin
  -Dversion=1.1

For a manual installation, you can download the plugin here:
http://www.apache.org/dyn/closer.cgi/java-repository/maven/plugins/maven-source-plugin-1.1.jar
         

Have fun!
-The maven team