Yeah it's making me a bit nervous as I'm on 2 flights on a 772 in the next few weeks. I normally schedule in extra time off after my return flight, but something came up the day after my return this time, so missing that return flight (which has been cancelled twice this month due to "maintenance") would be problematic. I'm flying out of LHR back to the US in the next few weeks - if it were to be cancelled for whatever reason, how quickly are they able to redistribute the passengers to other flights? From looking around it appears like most flights from LHR are not very full this time of year.