The PubCenter section of the Pipeworks manifest describes how PubCenter ads will be placed in a Win8 application.

Like the AdSense section, it requires an ID, and a BottomAdSlot or TopAdSlot are supported:

Here's an example:

            
@{             
PubCenter = @{             
ApplicationId = "1b9271e7-0be4-4ef1-84c3-9e8f921c1b4a"             
BottomAdUnit = "10048228"             
}             
}