This new HoloLens doesn't use a screen to merge its objects with reality, its lens allows light through like regular glasses and it paints its content directly on the back of the user's eyeball directly on the retina. This content can be seen even in direct sunlight and in a dim room could offer a totally immerse experience. They are imagining displays for soldiers like that first shown in the 1st Terminator movie where the real world is overlaid with additional information and analysis. Adding night vision cameras, infrared cameras, and ultraviolet cameras while at the same time offering AI to interpret the scene makes for a soldier that has a clear advantage.
I was attending TechCruch in San Francisco last year and a vendor demonstrated to me real-time time AI video analysis of people talking to the camera, the software could detect the person's heartbeat, respiration rate, levels of stress in the expression and determine whether they were agitated, nervous, angry, etc. That technology could easily be hosted on the Hololense and would be extremely useful on the battlefield and intelligence gathering.
In 10 years I expected smart phones, tablets, and even computers will be a thing of the past as regular looking eyeglasses will offer this technology. The only people who will have smart phones will be people with some sort of visual problem, who get nauseous, or freak out when using these displays. They will go the way of the pager.
Check out the demonstration of the HoloLens at the Mobile World Conference this week in Barcelona: https://youtu.be/c1CZsqwnWtM
The possibilities and the perils are endless.