As response for Twitter message: https://twitter.com/simenbrekken/status/529908576966688769

reflux_error_actions_to_notifications.js

var Errors = Reflux.createActions(['error1', 'error2' /*, 'error3' */]);

var ErrorNotificationStore = Reflux.createStore({
    init: function() {
        _.each(Errors, function(action) {
            this.listenTo(action, this.onError);
        }, this);
    },
    onError: function(errorMessage) {
        /* whatever you want to do with errorMessage and this.trigger(...) */
    }
});