Updated models with AMD graphics options expected in early 2017.
Apple Distributing Safari for Windows via iTunes
"We are using Software Update to make it easy and convenient for both Mac and Windows users to get the latest Safari update from Apple,"While the practice has generated some debate, ZDNet points out that Apple previously announced this plan at WWDC in 2007:
"Jobs said that Apple plans to use iTunes as a distribution vehicle for Safari for Windows. He noted that there are a million downloads of iTunes a day, with 500 million of those [having gone to] Windows machines."