For me the word "International" means that the airport provides customs facilities. Not such a big deal, besides you don't hear of Heathrow International or Gatwick International!
There are 33 million people within 2 hours car drive of Manchester. Suffcient catchment area, I would think, to support a fair number of daily intercontinental flights! I will admit that you won't tend to find too many in the front end of the planes but remember that we have an airline that prefers to shuttle passengers down to LHR rather than introduce long-haul out of MAN!
Looking at the situation pre-September, MAN was experiencing some 7% growth in passenger numbers; my website (http://fly.to/northwest-spotters
) has passenger statistics up to June for the international flights from Northwest England, although I have yet to upload the statistics for the picture to August.
Being specific to SQ, they along with MH and EK do well in providing connections to Australia. Once I am at home again, I will furnish a better response!
As for the ignorant comment about Man Utd, you may be surprised to learn that when they were relegated in 1973-4, the following season saw them have the highest average attendence in England despite being in the old Division 2. There's a lot of mythology about the attendences as they have consistently been in the top 2 or 3 even in the long, unsuccessful period that they had!
David/MAN: 237 and counting