Конфигурация Castle Windsor на основе файла сборки или конфигурации

Вот один из способов сделать это с помощью IHandlerSelector:

public class DebugHandlerSelector: IHandlerSelector {
    private readonly Type serviceType;
    private readonly Type debugImplementation;
    private readonly Type releaseImplementation;

    public DebugHandlerSelector(Type serviceType, Type debugImplementation, Type releaseImplementation) {
        this.serviceType = serviceType;
        this.debugImplementation = debugImplementation;
        this.releaseImplementation = releaseImplementation;
    }

    public bool HasOpinionAbout(string key, Type service) {
        return service == serviceType;
    }

    public IHandler SelectHandler(string key, Type service, IHandler[] handlers) {
        return handlers.First(h => h.ComponentModel.Implementation == 
#if DEBUG
            debugImplementation
#else
            releaseImplementation
#endif                    
            );
    }
}

Пример использования:

container.Kernel.AddHandlerSelector(new DebugHandlerSelector(typeof(IMethodService), typeof(MethodAService), typeof(MethodBService)));