Can't help but think STN would be a fine airport for DY to locate long haul services while maintaining European operation at LGW.
Why? What's the upside? Long haul yields traditionally follow the London Airport order of order LHR/LGW/ non existant. Why add the additional costs of a split London operation if there's no uplift in revenue?
The only reasons for any of QR/EK/EY to serve STN would be to attract passengers who they have not yet tied up via LHR/LGW. Now given QR/EY walked away from LGW I see little chance of an Essex outpost which leaves EK. Now they serve some regional airports covering the country well at the minute, it's not as if STN is a large untapped gap in the market. We're not seeing Stansted locals connect over AMS with KLM or FRA with LH even. That leaves pinching more pax off BA or cannibalising er....Emirates at LHR/LGW ! I could see a two class B77W though, if it works for NCL it could work for STN, the key issue for me would be the effect it would have on diluting loads or yields elsewhere at LHR/LGW.