gistfile1.js

/* SomeClass.js */

Class("SomeClass", {
    use : ["jquery.js", "OtherClass"],

    after : {
         initialize : function() {
             var thisInstance = this;
             use("jquery.js", function() {
              console.log("Jquery should be loaded here: %o", jQuery);
               use("OtherClass", function() {
                     new OtherClass();
               });
             });
         }
    }
});

/* OtherClass.js */
Class("OtherClass", {
     after : {
          initialize : function() {
                 console.log("I did not set jquery.js as dependency here, but it is still loaded, see %o", jQuery);
                 // this is a problem because it should not be available here!!!
          }
     }
});