C# 5 Async CTP

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Threading.Tasks;
using System.Threading;

namespace AsyncDemo
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        private Button _getDataButton;
        private ListBox _data;

        public MainWindow()
        {
            InitializeComponent();

            var grid = new Grid();

            _getDataButton = new Button {Margin = new Thickness(0, 0, 0, 272), Content = "Get my data!"};
            _getDataButton.Click += new RoutedEventHandler(GetMyData);

            _data = new ListBox {Margin = new Thickness(0, 45, 0, 0)};

            grid.Children.Add(_getDataButton);
            grid.Children.Add(_data);

            Content = grid;
        }

        async void GetMyData(object sender, RoutedEventArgs e)
        {
            AddDataToUI("GetMyData - Start - {0}", Thread.CurrentThread.ManagedThreadId);
            Task<int> calculationTask = Calculate();

            AddDataToUI("GetMyData.calculationTask - Start - {0}", Thread.CurrentThread.ManagedThreadId);
            int data = await calculationTask;

            AddDataToUI(data.ToString());
            AddDataToUI("GetMyData - End - {0}", Thread.CurrentThread.ManagedThreadId);
        }

        private async Task<int> Calculate()
        {
            AddDataToUI("Calculate - Start - {0}", Thread.CurrentThread.ManagedThreadId);
            Task<int> calculationTask = Task.Factory.StartNew(() =>
                                                            {
                                                                Thread.Sleep(3000);
                                                                return 10;
                                                            });
            AddDataToUI("calculationTask - await - {0}", Thread.CurrentThread.ManagedThreadId);
            int result = await calculationTask;

            AddDataToUI("Calculate - End - {0}", Thread.CurrentThread.ManagedThreadId);

            return result;
        }

        void AddDataToUI(string data, params object[] args)
        {
            _data.Items.Add(string.Format(data, args));
        }
    }
}