The recent blog post Keeping apps fast and fluid with asynchrony in the Windows Runtime includes examples of how the await keyword in C# and Visual Basic enables developers to use WinRT asynchronous operations while still maintaining and reasoning about good control flow.
In this follow-on post, I dive much deeper into exactly how await works with WinRT. This knowledge will make it easier for you to reason about code that uses await, and as a result, will enable you to write better Metro style apps.
To start, let’s ground ourselves by taking a look at a world without await…
via Diving deep with WinRT and await – Windows 8 app developer blog – Site Home – MSDN Blogs.