[FINoM]

wait = function(first) {
        return new wait.Init(first);
    }

    wait.Init = function(first) {
        var self = this;
        this.callbackCaller = function() {
            self.callback.apply(self, arguments);
        }

        first.call(this, this.callbackCaller);
    }

    wait.Init.prototype = {
        deferred: [],
        callback: function() {
            this.args = [].slice.call(arguments);
            this.args.unshift(this.callbackCaller);
            if (this.deferred.length) {
                this.done = false;
                this.deferred[0].apply(this, this.args);
                this.deferred.shift();
            }
            if (!this.deferred.length) {
                this.done = true;
            }

        },

        wait: function(run) {

            if (this.done) {
                this.done = false;
                run.apply(this, this.args);

            } else {
                this.deferred.push(run);
            }
            return this;
        },
        data: function(item, value) {

            if (arguments.length === 2) {
                this.data[item] = value;
            } else {
                return this.data[item];
            }
        }
    }

Так и не придумал, как коллбек всунуть в прототип: http://jsfiddle.net/finom/XSGub/64/