Sorry to burst the oh so precious LHR bubble, but I personally and all my friends, if we want a hub will go for AMS.
Cheaper, cleaner and more efficient than LHR. Always
And think of how many flights there are there daily from almost ALL the UK's regional airports, why the hell would anyone bother with LHR?
easyJet, KLM or Flybe to AMS is always far cheaper than an LHR fare.
LHR Hub? Maybe, but there are FAR better hubs to be had in Europe, better quality, lower cost.