I showed the following screenshot already in my previous blogpost about Windows Azure Active Directory. I told you I would show you more of it.
If you follow the Wizard, the site will go humming for a moment and the following appears. Your Website is connected to your Active directory.
The Federation Metadata document URL will be needed in a moment in Visual Studio.
It is a quick demo which the naming is showing 
I started Visual Studio and I did File –> New Project. Afterwards I choose my personal favorite a MVC 4 website. On the Web application portal right mouse click. You chose for ‘Identity and Access’.
Then take option 2 and copy the Federation Metadata URL from the portal in it.
Then F5 in Visual Studio. Your web application runt and shows the login window. I did not do anything.
If you use a user from your AD, that user will gain access to your amazing web application.
How cool is that! This opens a lot of superb possibilities for many companies and their private applications. This makes an Office 365 subscription even more interesting!
Ok, I tweaked it a little. Running it out of the box will give this error message. Some complaining about the Antiforgery token.
The solution is relative simple.
To revoke the Office 365 users access to the application. Click the following menu.
Choose the ‘Remove app’ choice.
And the users will get this fine error
Anyway, how cool is this. And I did not show you how you can access the AD User data via the WAAD Graph API. This will even extend the possibilities even more! But more about that in a future blogpost