Haven't there been rumors about this a few weeks ago? I remember reading something and then the next day I think someone from Intel or AMD said those rumors were not true....
Yet here we are a couple weeks later :))
Also, how is this any better than (for example) my laptop (Dell Inspiron 5567) that has both an Intel chip and Radeon R7 graphics? Other than the fact that these new chips will replace the integraded Intel HD Graphics and perform much better under load? I mean AMD's current mobile GPU offering is still stuck somewhere in 2014 (the Radeon R7M445 on my laptop built in 2016 is still 28nm and the die itself is huge compared to the i5-7200U it's connected to)
Also, I think it would be unwise to combine Vega with I-series chips... it would ruin Ryzen Mobile.