I'm not very excited about the product itself, but if you are at all interested in spatial computing, it's worth reading through Apple's design and developer resources:
While I don't think there will be a mass adoption by people willing to put on goggles throughout the day, it's clear that a lot of Apple's ecosystem is being directed toward environmental and situational computing, and the SDK backs that up. Using gaze detection to focus on more than one device in a room, surfacing certain interactions in specific rooms, and low-lag screen mirroring from devices are all pretty high-cost investments that are likely to find uses in other products. I look forward to what kinds of "continuity" type features this tech introduces.