PAXboy
I think its a long way from being 'game over'
LHR & LGW serve different markets, of course there is some over lap and some who fly from LHR would fly LGW if they lived South rather than North of London and the other way round.
Skippy has pointed out that LGW is not a true hub, although it does have some connecting flights and many DIY options.
LGW is the world's busiest single runway airport and heavily relies excellent ATC and mainly local based pilots who understand what is required, hence the fact that Turkish have had to have 'follow me' cars because they don't understand or comply !!
That it needs another runway is without doubt in my mind.
LHR needs either at least one additional runway or moving, the delays inbound even in good weather cost money, missed connections and a lot of additional fuel burn and pollution due holding, surely the whole point of an hub airport is reliability, come TS or stormy weather, BA will start to cancel the short haul stuff to the likes of LBA/EDI/GLA, thus encouraging long haul passengers to route through AMS in future.
At the end of the day it will be a political decision, but go back to 1997 and Lord Prescott said at the time 'do nothing is not an option' had Labour been elected in in 2010 then work would likely have been underway by now, the delay is an acceptable price for them not having be so elected, but this should not be allowed to go on for another 30 years.