AirAsiaX has 475 A320's, 51 A330's and 10 A350XWB's either on order or flying. Possibly, quite a few XAX's heading for EGSS from various Asian countries. I don't suppose they would be linking in to the, as yet unannounced, RyanairX transatlantic network would they?
http://http://www.airbus.com/newsevents/news-events-single/detail/airasia-x-orders-25-more-a330-300s/
http://http://www.bloomberg.com/news/2013-12-16/airasia-x-plans-to-sign-major-airbus-plane-order-this-week.html.
Of course there's no link between Ryanair and AirAsia. Or is there?
Airbus Says Low-Cost Airlines Will Keep Its A330 in Production for at Least Ten Years - Skift
So, 40 - 50 a/c required for a low-cost transatlantic operation. Presumably linking to a 40 - 50 a/c low-cost Asian operation. Mmm, I think a second runway may be going to be needed somewhere, pretty soon. But that's for another rumour!