In reply to Blobb:
If and if and if..
However, let's hypothesise.
If Scotland were to vote to separate from the UK I'd imagine that the EU would take the view that sooner or later Scotland would get back in and they'd wait until negotiations had ended before deciding what to do.
Anything else is sounds like a ginormous pain in the arse for the Eurocrats.
Re the UK. When Britain had a referendum to join the Common Market 60% of the population of the UK were against it at the start of the campaigns. By the end the proportion had reversed. I see the same thing happening this time round, if there is a referendum. Personally I don't think David will be back in Downing Street after the next election so let's not take things for granted here.
Of course whether it's a good idea for the UK or, in the unlikley event of a yes vote, Scotland to remain in the UK is in my view open to sensible debate.