There's no doubt that the snow in December caused disruption; travellers suffered particularly, with many sleeping at airports as snow-clearing continued. Heathrow Airport was hit badly with reported losses of £24m and in a further blow, airlines that had no choice but to cancel flights, are fighting to withhold airport charges. In reply to this, a statement by BAA can be viewed here.
As the UK's only major hub airport, Heathrow is significant in terms of number of destinations, flights and their frequency. The Economic Impacts of Hub Airports takes an in-depth look at Heathrow Airport - its medium- and long-term impact on the economy as well as the competition it faces with tables of statistics. Grounded : A New Approach to Evaluating Runway 3 is another report that may be of interest; the last few pages of this report contain links to further relevant material. 'Adding Capacity at Heathrow Airport' is now archived by the Department of Transport and can be accessed here.
BAA, the owners of Heathrow, have produced an Investor Report. A company profile is also available in Datamonitor 360 (Athens) which gives a history of the organisation, SWOT analysis and top competitors.