Got my first double upgrade from AA. Traveling DC to London, originally through Chicago, upgraded to biz on a VIP. Got rerouted through NY 3 hours before flight due to weather delays, but agent said "I can still confirm your upgrade." In NY, boarded plane, went to seat, and was confronted ten minutes later by someone holding a boarding pass showing the same seat number. At the same time my name was called on PA system, and purser said "I have bad news for you...you've been upgraded to first class." Was a little sad not to be able to try out new business class for first time, but somehow managed to suppress my disappointment I don't think reroute affected my fare class, as only economy miles/points awarded, so it seems there must have been very few (or no?) revenue passengers with status in business class....Its been a good year for op-ups--in addition to this one, I've had two from economy to biz out of Buenos Aires and London...