I agree fully with the comments by the author of bottle necks in the sky. In fact I said as much in Nagpur where they are thinking of building a Hub Airport. Today if Nagpur can get its act together and build an airport which can take the new Airbus A-380, it will be the only airport in India to handle this aeroplane.
Even if Mumbai and Delhi catch up later, congestion at these airports will make Nagpur more attractive for airlines who would like to get in, discharge passengers, pick up fuel and new passengers and take to the sky again.
Fuel burn is a very critical issue for airlines especially when large planes like the A-380 are forced to hold over congested airports.