not sure from these threads how much WinRT can be used to code desktop apps. Can a desktop app, that looks just like a WPF or Win32 app, be coded using WinRT?

http://social.msdn.microsoft.com/Forums/en-US/winappswithcsharp/thread/4e79b002-2361-4911-af49-0a8c47c1411b

http://social.msdn.microsoft.com/Forums/en-IN/winappswithnativecode/thread/ce649545-9ec6-45da-a4ee-71b9f2bed156

WinRT sounds terrific in terms of bringing XAML to native apps, deployment and siloing the app to avoid viruses.

If you can use WinRT to code a desktop app, would that app be able to run on Windows 7?  Where WinRT is installed on the Win7 PC just like .NET is installed on a PC to run a .NET app.