AMD just showed off their new 15W notebook-chips too. Being "APUs" they combine CPUs and GPUs - while this is not much different than what Intel is doing with their integrated GPUs, AMDs claims their GPUs are more powerful, while they seem to be able to compete even on the CPU side this time. Since Apple is already using AMD GPUs and is obviously valuing GPU performance in their Macs, I could actually see them using these chips over Intels, especially if the release timing is better. No words on higher powered 6-core chips for the 15" MBP though.
Too bad they compare the graphics performance to Intel's UHD 620, and not to the Iris Plus 650 - because they're about comparable to the latter and don't seem to have an advantage, according to the few benchmarks they're showing. But hey, at least Intel finally has got some competition again.
http://www.tomshardware.de/ryzen-vega-notebook,news-258649.html
(The article is in German, but the graphs do tell the whole story)