Some interesting comments, NQY could probably work a couple of times per week in the Summer, if timed right it could be useful for some inbound cruise passengers and outbound leisure travel (driving down to Cornwall in the Summer is a very slow journey so the option of flying down there in an hour could be quite appealing to some).
I have to agree that BMI regional would indeed be a good candidate to serve some business oriented European routes from SOU on their E135/145's.
Aer Lingus regional to Cork would be a logical addition to cater for the notable Irish population in the area.
Vueling would probably only work if Flybe were to drop the sun routes next year then they were to come in and 'save' them, which would hopefully generate them plenty of publicity. Of course it would be good to deal with the parking issue beforehand, but for a small operation they could try and mark out 2 larger stands across the existing stands 2-5 meaning 2 A320/738 sized aircraft could be handled at once.
KLM do effectively serve Flybe via codeshare so I would not expect this to change any time soon, though I expect AMS will eventually increase to 4 daily year round considering it has seen good increases in passenger numbers all year.
Air France to CDG would probably not add much to SOU, since KLM offer connections everywhere and Flybe's ORY service caters for the Paris market as well as some onwards domestic/French territories connections. HOP! could look at LYS & NCE I guess?
Iberia Regional would be a long shot, but could be possible if they decide to expand their UK presence in the future. What would a CRJ900 be like performance wise off of SOU's runway?
Finally I have mentioned it before but SOU fits well with Volotea in the sense that it fits their business model of avoiding competition from the main LCC's and the 717 is quite a good fit for SOU from both a runway performance and physical dimensions point of view.
