Paxboy,
The demand for hub connections that we failed to provide has already moved to the usual suspects on the Continent. We cannot get it back and the demand still seen is residual but America is in the same economic state as ourselves, so they are not going to be needing the kind of capacity that people talk about.
I don't agree - LHR is still Europe's busiest airport, and London the world's busiest aviation city, both measured by pax numbers. Also, CDG, AMS, MAD etc all have a fair amount of space given over to LCCs, artificially inflating their figures. Even FRA has Condor, Tuifly etc - and would AB get slots @ LHR?
You have to see the whole London picture - and that is both the problem and the solution. No other city has so many airports, we haven't learnt from the mess the Victorians left with so many different railway terminals!
But that is our lot, and we have to work with it - that is why BI can't work because it will be at such a massive cost disadvantage against all these other locations. LHR may get its 3rd runway, and BAA / FV seem to think there's a business case, although I still can't see the politics working.
Other commentators have suggested that LGW couldn't work either, as it is 'too far' from central London. LGW too far? And Boris Island?