Does anyone know how to provide credentials to a WebView control (or even better - run a Windows 8 Metro style application / WinRT app in the context of a specific domain us
In order to connect to sites on your corporate network you must enable the privateNetworkClientServer capability in your Package.appxmanifest. You can do this in the XML or you can double-click on the file in Visual Studio and use the designer (capabilities tab). In the UI it's called "Home or Work Networking".
Now that you have access to the intranet you can navigate to the site but you will be prompted to provide credentials. If you want the users domain identity to automatically be supplied (enterprise single sign on) you need to enable the enterpriseAuthentication capability as well. This is called "Enterprise Authentication" in the manifest UI.
From there you should be able to browse to any intranet site using a WebView and not have to authenticate. If you are looking to do things outside of the WebView, you should check out the following articles and samples:
Using WebAuthenticationBroker:
http://code.msdn.microsoft.com/windowsapps/Web-Authentication-d0485122
WebAuthenticationBroker has an option called UseCorporateNetwork. Make sure to use that when following along in the sample above.
Finally, if you want to do Single Sign On with other sites like Facebook or Flicr, see this sample:
http://msdn.microsoft.com/en-US/library/windows/apps/xaml/Hh465283