Saw this video on youtube: https://www.youtube.com/watch?v=s0t1wAkjFBo

  <quote>

NASA's Use of HoloLens Puts St. Louis Scientist on Mars with Curiosity Rover

If anyone sees Raymond E. Arvidson, PhD, walking the halls of Washington University wearing Microsoft HoloLens, then he's not entirely walking on Earth. HoloLens combined with OnSight, a software tool developed by NASA's Jet Propulsion Laboratory in collaboration with Microsoft, allows Arvidson to be absorbed in the Martian landscape conducting 'field' research. Arvidson may actually be walking on university flooring, but the software is allowing him to virtually walk on Mars with NASA's Mars rover Curiosity. In his role as Curiosity Surface Properties Scientist, Arvidson is planning Curiosity's next move.

  </quote>

Marketing material and PR stuff...a lot (IKEA catalogue, Lego boxes). I know it's used in warehousing (routes to locations of stuff, basically HUD of sorts) and it's used a lot for product demos/sales (think demoing some machine at a convention).

IKEA: https://www.youtube.com/watch?v=xC6t2eEPkPc Lego (oldish): https://www.youtube.com/watch?v=0uqxsIQNUPU

I've seen this company (http://www.specdev.com) demoing AR visualizations for wind farm development here in the Netherlands. I've also seen another company (which I don't recall the name) demonstrating a hololens app for maintaining wind turbines.