Async CTP exemplo 1

gistfile1.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Threading.Tasks;

namespace ConsoleApplication6
{
    class Program
    {
        private static int total;

        static void Main(string[] args)
        {
            IList<Uri> uris = new List<Uri>
            {
                new Uri("http://www.google.com"),
                new Uri("http://www.microsoft.com"),
                new Uri("http://www.devbrasil.net"),
                new Uri("http://www.yahoo.com"),
                new Uri("http://www.gmail.com")
            };

            var task = SumPageSizesAsync(uris);
            Console.WriteLine(task);
            Console.ReadLine();
        }

        public static int SumPageSizesAsync(IList<Uri> uris)
        {
            var tasks = new List<Task>();
            foreach (var uri in uris) 
            {
                Console.WriteLine("Verificando: {0}", uri);
                tasks.Add(Total(uri));
            }
            while (!tasks.All(x => x.IsCompleted)) {}
            return total;
        }

        private static async Task Total(Uri uri)
        {
            var data = await new WebClient().DownloadDataTaskAsync(uri);
            total += data.Length;
            Console.WriteLine("\tVerificado: {0}\n", uri);
        }
    }
}