If project.getConfiguration().getString(CI_URL_PROPERTY) does not return a URL (CiManagement property is blank, as is the case of a new project in Sonar) and the project.getPom() is null, a NPE is thrown by the project.getPom().getCiManagement() call.
I am attaching a patch that I have used to fix the issue for my system.
Install the Build Stability plugin in Sonar and Hudson
Configure the Hudson plugin
Configure the Sonar plugin
Create a new job in Hudson (Not Maven, no POM) and use the 'Invoke Standalone Sonar Analysis' to publish the results to Sonar
Execute the job on Hudson and you should get an NPE from the Build Stability Sonar plugin