The actual service - map as a singleton and use getInstance to make it come to life

InterestingEventTypesLookup.as

public class InterestingEventTypesLookup {

    protected var _eventClassesByType:Dictionary;

    public function get eventClassesByType():Dictionary
    {
        return _eventClassesByType ||= new Dictionary();
    } 

    public function appendEventInterest(eventClass:Class, eventType:String):void
    {
        eventClassesByType[eventType] = eventClass;
    }

}

LoggingBootstrapCommand.as

public class ConfigureLoggingCommand {

    [Inject]
    public var interestingEventTypes:InterestingEventTypesLookup;

    public function execute():void
    {
        // for each event you care about
        interestingEventTypes.appendEventInterest(SomeEvent, SomeEvent.SOMETHING_WENT_DOWN);    
    
        // then bring the actual logger to life
        injector.getInstance(LogginService);
    }
}

LoggingService.as

public class LoggingService extends Actor {

    [Inject]
    public var interestingEventTypes:InterestingEventTypesLookup;

    protected var eventMap:EventMap; // copy the event map imp from Mediator

    public function LoggingService()
    {
        registerListeners(); 
    }

    protected function registerListeners():void
    {
        var eventClassesByType:Dictionary = interestingEventTypes.eventClassesByType;
        for (var eventType:Object in eventClassesByType)
        {
            var eventTypeStr:String = eventType as String;
            var eventClass:String = eventClassesByType[eventType];
            
            eventMap.mapListener(eventDispatcher, eventTypeStr, logEvent, eventClass);
        }
    }

    protected function logEvent(e:Event):void
    {
        // do your thang with the event
    }
}