function MyController($scope, $q, $timeout) {
    this.getItem = function () {
        var deferred = $q.defer();
        deferred.resolve({
            title: 'Some title'
        });
        return deferred.promise;
    };

    $scope.item = this.getItem();
}

<input type="text" ng-model="item.title">

this.getItem().then(function(result) {
   $scope.item = result;
});

this.getItem = function () {
    var item = {};

    // do some async stuff
    $http.get(...).success(function(result) {
       item.title = result;
    });
    return item;
};

$scope.item = this.getItem();

$timeout(function(){
   $scope.item = {
      title: 'Some title'
   }; // Apply the binding
   deferred.resolve(); // Resolve promise
},2000); // wait 2 secs