the idea of the cabin part being an installable/changeable part is something i had many years ago (at least a decade ago) ...whilst waiting again and again at airport boarding areas and finding it the most inefficient part of the process - even when treating aircraft more like buses (ryanair BMI baby easyjet etc).
load passengers into pod.... move out to location, slot into fuselage (shortly after the arriving passengers have been de-docked in similar fashion). I'd expect this to only be for the short-haul rapid turnaround commuter style flights.... the long-hauil stuff - you want more comfort/opulence and 15/20 minutes extra boarding time isnt much on a 17 hour flight.
but as the article says...for emergencies? not really.