Google has acknowledged that their vision of where this is going is, at best, partial: "While we may believe we know where this technology will take us, history suggests we that should be humble in our predictions. We are excited to see the effort take shape with each step forward."
I liked this part.
Google Maps already has indoor maps.
This is an unveiling of a technology but the "applications" they show in this video are probably a waste of time to most users. Google have not shown a killer app that uses this tech. Maybe they're working on something (they hint that they may be planning to integrate indoor mapping into Google Maps which might be interesting) but they're not showing it in this video.
That doesn't mean the tech is bad. But we haven't seen enough to judge it as useful to end users.