Problem solved!
Downloaded the identity-manager version which is used for the wso2IS 4.6.0:
http://svn.wso2.org/repos/wso2/carbon/platform/branches/turing/components/identity/org.wso2.carbon.identity.mgt/4.2.1
The class IdentityMgtServiceComponent is registering the IdentityMgtEventListener as an service in the Osgi-Context.
IdentityMgtServiceComponent:
protected void activate(ComponentContext context) {
listener = new IdentityMgtEventListener();
serviceRegistration = context.getBundleContext().registerService(
UserOperationEventListener.class.getName(), listener, null);
Finally I copied this pattern and wrote my own bundle with an extension of AbstractUserOperationEventListener and activated it via a bundle-loader-class.
All the pre/post add/delete actions are triggered fine.
Hope this helps