1. There's a neat hardware size progression for ML that was posted on Twitter: MagicLeap's gone from a device like you stare through at the optometrists office down to something comparable to a scuba mask.
https://twitter.com/karanganesan/status/1024970520205307904?...
2. There are a few different ways to achieve AR style displays and what Magic Leap has chosen is the hard way -> lightfields and eye tracking (two technologies that haven't really been attempted to ship at scale).
3. This is still a developers' release - and not truly a "paradigm shift" or whatever overhyped term you want to use.
Separate from all that, I still think the end game of AR (in the next 10ish years) is to be the thing that comes "next" after smartphones. The proper way to view this ML Dev kit is that it's the equivalent to a PalmPilot or other barely functional PDA that had some good ideas, but didn't quite hit the right inflection point of portability, screen, battery life, form factor, etc. but that paves the way to get there.