Updated models with AMD graphics options expected in early 2017.
Apple Offering Free Licensing of Mini DisplayPort Spec
This licensing news adds some clarity to the debate about whether or not the Mini DisplayPort was a proprietary solution from Apple alone. The no fee license should allow 3rd party manufacturers to integrate the port into their own products and also to develop additional useful adapters. For example, Apple currently doesn't offer the appropriate adapter to allow customers to connect older Macs to their new 24" Apple LED Cinema Display.
Apple has said that they will be integrating the Mini Display port into all future products.