I don't think so. In a recent trade-paper interview, O'Leary, CEO of Ryanair negated chances that Ryanair would fly long haul. They have intentions of buying Aer Lingus, Irish flag carrier, which operates long-haul routes.
But Ryanair flying long-shaul, that's a long shot.
There have been some attempts in the past for low-cost US airlines to fly long haul, and all have failed. Some successfull Southwest clones in the 80s have tried flying long haul from US (NYC) to Europe (don't rember the name) and AFTER the attempt they went bankrupt.
So, I don't think so..... about the Ryanair.
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UPDATE:
O'Leary told trade magazine Flight International that the new airline could fly to five or six U.S. cities from European bases and offer one-way fares as low as $12. It would serve secondary U.S. airports such as Baltimore and Providence in Rhode Island and would also have "premium class" seating.
......
"By mid-2009, we will be carrying 70 million passengers at 23 bases across Europe," he told the magazine. "It will be relatively straightforward for us to do a deal for 40 to 50 long-haul aircraft and connect these bases trans-Atlantically."
What this wants to say: Ryanair has 23 bases. This means "focus-cities", not that it would fly from 23 European cities.
It would be possible for them to ORDER (financially) up to 40 long-haul aircrafts. It does not mean they are oredring them, or that they will.