Given that jet fuel has averaged just over $3/gal so far in 2011 and doesn't look to be dropping (unlike crude prices, which have collapsed), it shouldn't surprise anyone to see marginal routes eliminated. Fuel will likely cost AMR more this year than in 2008 when it last spiked, and the economy is certainly weaker this year with no improvements on the horizon. Unless things begin to improve, look for more downsizing and route cancellations/suspensions.
During the peak season, AA and BA run 51 daily flights to London from the States; BRU is an easy short connection away from LHR. It's not unlike a London-originating traveler being forced to connect if their ultimate destination in the USA is not among the AA/BA LHR gateway cities. There are quite a few USA metro areas with a million people that don't have nonstop AA/BA service to LHR, and there will be plenty of large, important cities in Europe that AA/BA can't economically serve with nonstop flights.