Here is a pure javascript asset loader as a Curl.js module. You create a new instance of it each time you want to load assets. Pass it an object with an "assets", "onComplete", and optionally "onProgress" properties. It does the hard work for you.

gistfile1.txt

define(function() {

  function BulkLoader(options) {

		new LoadingGroup(options.assets);
		
		//Wrap the image loading so we can identify the asset 
		function ImageLoader(url, id, callback){
			var _id = id;
			var _url = url;

			var _img = new Image();
			_img.onload = function(){
				callback(_img, _id)
			}
			_img.src = url;
		}

		function LoadingGroup(images_array){
			var output_images = [],
				i;

			//store array of statuses
			var loaded_status = [];
			for(i = 0; i < images_array.length; i++){
				loaded_status[i] = false;
			}

			//generate new loaders. Have them check the status when they're done
			for(i = 0; i < images_array.length; i++){
				new ImageLoader(images_array[i], i, checkStatus);
			}

			var filesLoaded = 0;

			function checkStatus(imageData, id){
				//update its status
				loaded_status[id] = true;
				output_images[id] = imageData;
				filesLoaded++;

				if(options.hasOwnProperty("onProgress")){
					options.onProgress({
						loaded: filesLoaded,
						total: images_array.length,
						percentage: (filesLoaded / images_array.length) * 100,
						id: id,
						data: imageData
					});
				}


				//check if any status is still false
				for(i = 0; i < loaded_status.length; i++){
					if(loaded_status[i] == false){
						return;
					}
				}

				//if it makes it here, all images are loaded
				options.onComplete(output_images);

			}
		}
	}

	//that's all.
	return BulkLoader;

})

/*
Implementation
*/
//bulkloader example
  	var loadGroup = new BulkLoader({
			assets: ["../images/title_magic.png","../images/asfalt.png","../images/logo2.png","../images/logo.png"],
			onComplete: function(images){
				console.log("images done");
			},
			onProgress: function(options){
				//an image is finished
				console.log(options.percentage + '%');
				console.log(options.loaded + " of " + options.total + " images were loaded.");
				console.log("#" + options.id + ":");
				console.log("data:", options.data);

				switch(options.id){
					case 2:
						console.log("The third image was finished loading")
					break;
				}
				
				
			}
		})