The rumour circulating is that the 330 lease is all part of an operation trial for the alleged forthcoming airbus order.
They trialled the narrowbody product at NCL last year with the Titan A320 wet lease (did seem a bit odd at the time, didn't it?) and that the 330 wet lease next summer is the widebody trial. It'll stay shorthaul next summer, but they're looking to order 330s for operation to Florida /Caribbean at some later date, but will shove it on the upcoming narrowbody order for max discounting.
That's the rumour.