Donington Hall would never be sold to a housing developer - grade II*, oval stair hall, ceilings and friezes in Adam style, ionic pilasters, Jacobean-style fireplaces. Not a chance they would carve that into flats.
On the subject of Regional, do you think that Flybe would want it? Completely different route structure, operates into a load of different airports (that could be good if Flybe look to expansion, but they may wish to focus on Nordic first) and mainly services oil industy. With Connect there was the fleet overlap in the Dash 8s and the 146s/RJs - and the 135s which were/are continuing to be (not sure which) retired. There was also the element of removing the competition which Connect had previously posed.
Jet2 would obviously be very keen on baby although this would nearly double their size? Also, could they find the money?
Lufty/BA will have an interesting time convincing unions and competition commissions that a mainline selloff to them would be a good thing. We will have to see.