Of course they will use base stations. Here the idea is to bring the signal to some local base station to spread the connexion to people.
Wifi is designed for "home" use, not for more than 100m (and even 50m...)
Here the idea is to avoid the use of massive and expansive cables, it could be an idea for hard-to-reach-areas, such as mountains or islands.
However as many research project, it is probably a big dream which will provide some side-effect-technologies which will be used by consumers.
I don't really expcet to see any ballon away from experimentations. Remember the last big balloon authorized over NewYork? Zeppelin proved us we cannot so surely rely on ballons.
But the dream is big and it will definitly bring up great innovations!