Davies 2013 interim report
The 1st question the Davies Commission needs to decide is whether the UK wants a single hub airport or multiple hubs; this will set the framework on which SE airport expansion and additional runways can be decided. Common sense dictates this decision should be made in the 2013 Interim Report, as LHR's owners need certainty as to whether it will be closed if a Thames Estuary airport is built and/or if they will be allowed to build any new runways.
Even if Davies rules against any additional LHR runway(s) there is still huge potential for increasing its passenger numbers arising from the "Toast Rack" rebuild of the terminals and stands. In fact BAA are cutting off their nose to spite their face in delaying the toast rack work, as they will want the additional passenger capacity; a possible short R3 is not intended to reduce the existing 480,000 atms on the two main runways, which will be filled up sooner or later with larger capacity aircraft requiring better facilities.
The owner(s) and airlines of LHR naturally want it to remain the only UK hub; though the Competition Commission did not agree when it ordered BAA to sell both LGW & STN. The new owners of LGW have no intention of allowing it to be used as a LHR annex; rather they want it to develop as a freestanding hub in its own right with improved rail links to London.