According to our sources, Apple is pondering about using custom x86 CPUs in its next iMacs and MacBooks, during 2017-2018. Nowadays it's hard to avoid the use of x86 ISA in high end and professional personal computers, but at the same time Intel CPUs are too expensive if we compare these with ARM SoCs.
http://www.bitsandchips.it/52-english-news/6183-apple-could-use-custom-x86-soc-made-by-amd