If you aren't using Maven for the first time then it's recommended that you clean your local maven repository:
Unix
~/.m2/repository/
Windows
%USERPROFILE%/m2/repository
Open a shell and add JAVA_HOME and MAVEN_HOME environment variables to your path.
Run the command mvn install from your trunk directory.
Note A separate download and installation of the JAX-WS RI is no longer required because the relevant jars are now available on ibiblio. A big thank you to the people who helped to make this happen.
Steps to configure Eclipse for Yoko development
Run the command mvn -Peclipse from your trunk directory.
This will generate Eclipse .project files for all yoko modules.
In Eclipse, make sure you have a Java5 installation as your default JRE. Chose Window >> Preferences >> Java >> Installed JREs.
Choose File >> Import... and pick Existing projects into Workspace (located in the General category).
Select the yoko trunk directory as the root directory for the import.