The Oil Spill move to Cardiff is quoted as an interim measure, although admittedly once they're in it might be hard to tempt them back out. Cardiff has no more hangarage than we do and they'll want some so I guess it could come down to who's willing to build some first? TUI have announced extra capacity at EMA, LBA and MAN but it amounts to nowhere near the four or five aircraft based at DSA so don't rule them out just yet. Wizz is the kick in the teeth, given we had them before, coupled with the website leak last year that suggested a deal was at an advanced stage, they should have been an achievable target.
You didn't mention NPAS, who have been linked with both Birmingham and Leeds East.