Gonzo/Jerricho
sorry for having misleaded you writing "artificially capped". probably, I should not have used "artifically", but "voluntarily"!
What I meant was simply that politician, BAA, etc. are not giving LHR the attention it really deserves (but this is probably a problem common to many airports all over the world).
BAA, for example and I believe I am pretty sure, is by far more concerned in having T5 opening asap and its retailers running their cash teller at the maximum (actually, considering the increasing time tha paxs wander in a terminal, I woul suggest BAA to install slot machines in all passenger area!).
New taxyways, different taxyway layouts, etc., are ranking in the bottom section of their priority list. BAA for sure will fixthe problems arising form having A-380s on the tarmac at LHR, but with minimum possible investment (i.e. money) required.
Politicians? For them LHR is a terrible headache, a very big-big problem. So the cure is ... try to look at it as much later as possible (sorry, when next elections are due in the area?).
So BAA in a win-win position ($, £, euro, whatever currency is welcome!), politicians in the usual "political" situation they love so much ..., and the losers are ... the pilots and the ATC people!
Possibly - as Jerricho wrote - the best thing for LHR is: Nuke it and start again!!!
P.S.: my personal airport black list ranks LHR numers three after MXP (by far in pole position) and FCO.