JavaScript Sandbox Pattern

Based on this Stack Overflow question I came up with the following code. I'd like your general thoughts about it. Code style, functional, logical, disadvantages, just anything you can come up based on the code that should be mentioned about it and springs into your eyes.

This is the sandbox:

function Sandbox() {
    // turning arguments into an array
    var args = Array.prototype.slice.call(arguments),
    // the last argument is the callback
    callback = args.pop(),
    // modules can be passed as an array or as individual parameters
    modules = (args[0] && "string" === typeof args[0]) ? args : args[0], i;

    // make sure the function is called
    // as a constructor
    if (!(this instanceof Sandbox)) {
        return new Sandbox(modules, args[1], callback);
    }

    // if supported use old values
    if (undefined != args[1] && "object" === typeof args[1]) {
        this.loadedScripts = args[1].loadedScripts;
        this.eventHandlers = args[1].eventHandlers;
    }

    // now add modules to the core 'this' object
    // no modules or "*" both mean "use all modules"
    if (!modules || '*' === modules) {
        modules = [];
        for (i in Sandbox.modules) {
            if (Sandbox.modules.hasOwnProperty(i)) {
                modules.push(i);
            }
        }
    }

    // always load internals
    Sandbox.modules['internal'](this);

    // initialize the required modules
    for (i = 0; i < modules.length; i += 1) {
        var module = modules[i];
        // load modules if not present
        if (typeof Sandbox.modules[module] == "undefined") {
            $.ajax({
                async : false,
                dataType : "script",
                cache : false,
                url : 'js//modules/' + module + '.js'
            });
        }
        Sandbox.modules[modules[i]](this);
    }

    // call the callback
    callback(this);

    // any prototype properties as needed
    Sandbox.prototype = {
        name : "Sandbox",
        version : "1.1",
        getName : function() {
            return this.name;
        }
    };
};

// set space for modules to add to the sandbox
Sandbox.modules = {};

Sandbox.modules.internal = function(box) {
    var box = box || {};
    box.eventHandlers = box.eventHandlers || [];
    box.loadedScripts = box.loadedScripts || [];

    box.loadScript = function(options) {
        var urls = options.urls || options.url || [];
        urls = $.isArray(urls) ? urls : [ urls ];
        $.each(urls, function(index, value) {
            if (-1 == $.inArray(value, box.loadedScripts)) {
                $.ajax({
                    async : false,
                    cache : false,
                    url : value,
                    success : function() {
                        box.loadedScripts.push(value);
                    }
                });
            }
        });
    };

    box.removeOldEventHandlers = function(options) {
        if (box.eventHandlers.length > 0) {
            for (key in box.eventHandlers) {
                if (box.eventHandlers.hasOwnProperty(key) && /^0$|^[1-9]\d*$/.test(key) && key <= 4294967294) {
                    box.eventHandlers[key].off(); // remove event handler
                    box.eventHandlers.splice(key, 1); // remove from array
                }
            }
        }
    };
};

Here a sample module ("comment.js"):

Sandbox.modules.comment = function(box) {
    var box = box || {};
    box.loadScript({
        url : "/js/template.js"
    });

    box.addComment = function(options) {
        var templateURL = options.templateURL || 'templates/comment/comment.js.tpl', commentsContainer = options.commentsContainer, trigger = options.trigger, text = options.text, guid = options.guid, newComment = $('<article style="display:none;"><img src="images/ajax-loader.gif" alt="loading comment" /></article>');

        newComment.prependTo(commentsContainer).show('fade', function() {
            $.post(SERVICE_URL, {
                o : 'comment',
                f : 'add',
                set : {
                    text : text,
                    id : id
                }
            }, function(response) {
                if (-99 == response.header.code) {
                    newComment.setTemplateURL(templateURL).processTemplate(response.content).fadeIn();
                } else {
                    box.buttonMessage({
                        message : response.header.userMessage,
                        button : trigger,
                        title : 'Error!'
                    });
                }
            }, 'json');
        });
    };
};

Here is the call to a modules function ("addComment.js"):

var Sandbox = Sandbox([ 'comment', 'message' ], Sandbox, function(box) {
    // add comment
    var trigger = $('#button_addComment'), comments = $('#comments'), commentsContainer = $('#commentsContainer', comments), input = $('#text', comments);
    box.eventHandlers.push(trigger);
    box.addComment({
        text : input.val(),
        guid : comments.attr('data-guid'),
        trigger : trigger,
        commentsContainer : commentsContainer
    });
});

And here the actual call to the code:

var SERVICE_URL = 'service.php';
$(function() {
    $('section#addComment').on('click', 'button.button', function(e) {
        e.preventDefault();
        var name= $(this).attr('id').split('_')[1];
        //getCachedScript is just the $.ajax equivalent of $.getScript but with caching
        // this would load "addComment.js"
        $.getCachedScript( "js/app/" + name + ".js" ).fail(function() {
            alert("This function is temporarily not available");
        });
    });
});