Here is a list of items that are tested in your Windows 8 App. If you are in Southern California, please email these posts for more information on getting a token for your app by June 30, 2012!

 

Windows 8 will be available for a myriad of devices, form-factors, resolutions and aspect ratios.
If you want to sell to all these devices, you must design a flexible layout that adapts to this wide variety of devices and aspect ratios.
You should also design for different resolutions and include assets that will look great in high-resolution displays.
We recommend you test your app at all the following display resolutions: 1024x768, 1366x768, 1920x1080, and 1280x800.

Reference (HTML)

http://msdn.microsoft.com/en-us/library/windows/apps/hh465386.aspx

Reference (XAML)

http://msdn.microsoft.com/en-us/library/windows/apps/hh465386.aspx