Windows 8 will include a new Start screen similar to Windows Phones. The Start screen will have tiles that represent programs. Clicking on a tile will start the program. The thing that makes a tile different from an icon is a tile can contain live information. For example, the tile for an e-mail program might include the number of messages in the in-box. Tiles are also big. This allows them to not only contain live information, but also makes them optimized for touch screens.
When a tile is selected, a traditional Windows application or a Metro-style application might start. Traditional Windows applications will run on the Windows desktop. Metro-style apps will run in full screen, like an application on a phone or tablet. Metro-style apps will also have their own controls and idioms optimized for touch. Microsoft has claimed that in a couple years nearly all computers will have touch-enabled screens.
First, Microsoft is not “killing” Silverlight. Silverlight will be used where appropriate. For example, when a program needs to run on both a PC and a Mac.
Third, the .NET Framework is not going away. WinRT applications will still need to access services, write to databases, and not all applications will be Metro-style applications.
Windows 8 and Metro-style apps offer exciting new opportunities for developers. Whether you are a C++, Web or .NET developer, you will be able to leverage your existing skills to create great new applications for you users. If you want to learn more about developing Windows applications using XAML come to Learning Tree course 975: WPF and Silverlight Introduction: Hands-On.