Don't forget the cargo operators. The cargo market is growing with double digits for years and years; outside the public focus, FedEx and UPS are growing to airlines as big as UA, AA... I would expect either these, Polar or Atlas buying some cargo A380s. Maybe not now, but around 2008 there sure are some US A380s.
UA and NW might buy some when seatmileprices of the A380 are favorable and they have substantial routes for the aircraft (only a fleet of 10 to 15 aircraft on the minimum would make sense, otherwise they'd better let two 744s do the same job as one A380.
nobody has ever died from hard work, but why take the risk?