The best possible business apps, including the Thyssenkrupp promo, revolved around conferencing with people in real time in an augmented reality space. Someone can help you while viewing what you're seeing, and interact with you using holograms, files from your OneDrive, and of course video chat. The Skype demo is by far the best implementation I've seen of this, and it's designed really well imo. The other user does have to download a skype plugin, but then they are able to interact with your space.

I've yet to test it with two devices, but there's a lot of shared experience functionality in the HoloToolkit.