There will be no additional space. Terminal 5 will open, and simultaneously Terminal 2 will close for rebuilding

And how can there be improvement at BAA when it is already running optimally - for shareholders profits - by minimizing expenditure on maintenance (baggage-belts, escalators and cleaning) while optimizing parking-revenues and concession-sales by maximizing discomfort and delays for passengers.

Edit: It's a mind-boggling conflict of interest. Anyone who has passed through LHR will know the feeling, that someone or something is deliberately trying to make this a lousy experience for you. It's BAA, maximizing their profits.

BA too is chronically understaffed, in the baggage-hall for example your first thought is that the BA minders must be playing hide-and-seek behind the mounds of luggage, but there's really no-one there at all.