The way I see it expanding now would be to try and attract more business from Eastern Europe. We have a few Polish options but Hungary, Slovakia, Czech Republic, Romania, Bulgaria and the Baltics all have routes that could work from here. Could Wizz venture up the M1?
Wizz already has; they're ensconced in Doncaster. I was looking at the airport's website only at the weekend and amazed by just how many destinations they serve from there. They serve a particular market, "gastarbeiter", working in the agriculture / horticulture / food processing industries.
Despite UKIP's protestations there aren't that many Romanians in UK, so I can't see the likes of Bucharest, Timisoira and Cluj working outside the magnet that is London. It's important to remember that to many non Brits. the UK is London, and London is the UK!