Updated models with AMD graphics options expected in early 2017.
Evidence of Apple Maps for OS X Shows Up in iOS 6 Beta
In this XML file, there is a reference to a set of Intel based graphics chipsets for which certain features like Shading are disabled.
Cody says that older Intel chipsets are known to not support shading very well, and that’s probably why Apple wants to disable that feature on these Macs or will be software rendered.
It is unclear exactly what form Apple's maps would take on the Mac and whether the references are simply for hooks into map-enabled apps on OS X or if there is some more significant mapping solution coming to the Mac.
Apple's new mapping system is a key feature of iOS 6, enabling Apple to break free of the Google Maps relationship it has relied upon since the iPhone's launch in 2007. Apple's maps, developed in partnership with TomTom and other providers, will include integration of Siri with turn-by-turn directions, "Flyover" 3D-view imagery, and integration with Yelp for local search information.
Update: As several readers have noted, with the files being inside the iPhone simulator package, it is possible that the references are merely addressing functionality of the simulator to allow developer to test their apps without an actual device.