Well they've cornered the short and long haul market, with Easy's marketing clout they could make a convincing argument for the public to go Orange across the pond, even it wasn't that much cheaper than the full-fare boys. As long as the perception that Easy is cheaper was there, then they're onto a winner.
In terms of fleet, I always thought the 75 was a good ecomomical choice, but that doesn't fit in with their fleet plans. Could an A321 do it?