Yes, they sure have, but I believe the -10s will be with us for at least a part of the Summer season. I guess the fuel burn per seat is well up on the A330, but they're fully written down so I'd have thought financially they're worth keeping on. You can buy an awful lot of fuel for $100 million!
Until such time as passengers refuse to fly in them and/or maintenance costs get prohibitive, I can't see the problem. They could do with a new coat of paint, mind.
Cheers,
TOO