[quote author=Federico Fissore link=topic=237171.msg1704755#msg1704755 date=1398964855]
From the MCU point of view, a Yun is a Leonardo. Not every shield works with the leonardo. Some/most (I don't have a number) work fine by overriding some pin numbers in the related library
To give you an example, see this tutorial, the leonardo paragraph in particular
[/quote]I think there are just too many people that just don't read any documentation, regardless how many times you push their nose onto it... 
Ralf