It will, for sure, improve some human-computer interactions in a few domains where it is easily deployable (mainly entertainment and industrial manipulations).
Other than that, I don't see it used that much. It is still cumbersome to wear, doesn't seem to be usable in mobility, and won't solve common problems in a business environment.
(But I'm still waiting for it, heh.)
It literally makes your desktop into a big screen display floating right in front of you. For a background you can have a space scene with a planet similar to Saturn and asteroids floating around you. Immediately I fired up and watched 2001 A Space Odyssey on my new virtual big screen display. I could also work on code in any editor.
It's just your desktop in virtual space. But this gives me some neat ideas, especially business applications. Startups that exist only online are not that uncommon. Imagine a virtual office application where employees across the world can work together in a virtual space. It could be a office setting or on the bridge of the Enterprise. Each employee has a workstation with displays that you could check out in real time. For example, say you're having an issue with a database, you could get up and move over to the work station of your admin and help resolve it and see what he does on his screen. You could have meetings on the moon. And all while working from home, thousands of miles apart. Combined with voice group chat, it could be a killer app.
As someone working on an indie studio in Texas, with my partner based in New Jersey, the idea of doing that makes me very excited.
Lighthouse is really exciting in that way because being able to get peripherals into virtual space accurately would be a boon.