Interesting debate re long haul but I suspect not all contributors have much experience of the matter even as a mere passenger like me.
The BA bashing is tiresome really - it's a private business, not the Ministry of Aviation and they have a right to operate where they feel they can make (most) money - like any other airline. I tend not to use BA myself as I don't like the drag of LHR - and yes even T5 - but to say that Northern folk 'are increasingly refusing to use them' smacks only of sour grapes. I wonder whether the so-called goodwill that people talk about on here is only amongst the aviation enthusiast community, as most people I know don't give a hoot. A friend of mine, living only 20 minutes from Manchester Airport, who regularly travels business class to the US - including to a place that has a daily non stop from MAN still insists on flying to LHR and back across with BA because he collects BA miles, He gets enough over the course of a year to pay for a nice family holiday. That sort of thing goes on quite a lot whether we like it or not.
In terms of further long haul expansion to the east from MAN, good news as Emirates is, it was one more nail in the coffin in terms of other airlines trying new routes. One possible exception is HKG because the numbers might make a non stop work, but that would be it.
A couple more points based on the real world of people who actually do the flying that creates the demand for these routes and airlines:
1. To make any long haul route work for business pax really, you need a daily service, There would be no way I would stay an extra day in some far flung destination to wait for a direct service to MAN when I could get back to the family through a usually wide range of options, a whole day sooner. Something like a 2x weekly to (say) Beijing would likely end up with a full back end of aircraft with people who don't mind when they travel as long as it's cheap.....and a near empty front end as the business passengers will have made other arrangements. Result: failed service.
2. Those that talk about Emirates and their great connections to China, obviously haven't had to do that on business unless they like sitting in aeroplanes. If you're in MAN and need to go to Beijing you would probably go with Lufthansa or Finnair, I've tried most of the viable options and those are the best,
Reality check over.