At the heart of Windows 8 development is WinRT. This is NOT Win32 and it’s not .NET. It’s a brand new set of APIs that’s designed for modern software development and designed for user experience with an asynchronous model that allows your app to remain fast and fluid.
All of this new functionality is available in addition to the ways you’ve always done things. It does not eliminate it. So you can still write web apps, .NET apps, and native apps against Win32 like you always have. That’s excellent.
In case it’s news to you, here’s an API overview of the Windows 8 Platform. You can find more information at buildwindows.com and dev.windows.com.