I think the author mostly has a point with regards to backwards compatability; however, mobile app development is already centered around OpenGL ES graphics, so I don't see it as a major stumbling block for new code. Of the three points he made, the shift from XRandr to mode-setting sounds like the most potentially troublesome.

There was a presentation on the mode-setting architecture at FOSDEM in February, I'm going to look at it now: http://www.phoronix.com/scan.php?page=news_item&px=MTI5N...