It is interesting that when Cameron, Rajoy and Barroso make comments about the difficulty that newly independent nations might have in remaining in the EU they only concentrate on secessionist movements in Spain and the UK, they forget about the third EU member state that has secessionist issues and is, possibly, more likely to split than the UK or Spain – Belgium!
If a newly independent Catalonia and a newly independent Scotland might find continuing membership of the EU difficult, if not impossible, then the same MUST be true of a newly independent Flanders and a newly independent Wallonia! And therein lies a rather interesting problem, in that the EU could find itself in a position where its parliament and headquarters are in a country which would find it difficult, if not impossible, to remain in the EU.
Any scenario that envisages Brussels being kicked out of the EU is based on abject stupidity, of course. It would never happen, it could never happen; but remember the basis of the scenario is the exact same stupid argument as Cameron, Rajoy and Barroso are making about Scotland and Catalonia's continued membership of the EU!