Where is WebClient.DownloadStringTaskAsync(Uri,CancellationToken) in VS11

Question

In the Async CTP there is an extension method with the signature

WebClient.DownloadStringTaskAsync(Uri,CancellationToken) 

Where is this in VS11?
Do I need to install the Async CTP to get this method?

Answer 1

In .NET 4.5, you would probably use the new HttpClient Class, in particular the GetStringAsync Method.