Yugoslavia is not a great comparison with Spain, Yugoslavia had ethnic and religious hatreds at its core, it was only kept running by the strict rule of Tito and collapsed when he died. Catalunya is an odd one, there is definitely a distinct identity, as all regions of Spain have, but the nationalist movement seems to be mainly a movement of the bourgeois and privileged (i.e brats like Pique). Catalunya is an immensely wealthy region and I find the independence movement to be quite a selfish movement, certainly in comparison to other modern nationalism like in Scotland which is primarily a left-wing phenomenom.
That being said, who the hell am I to judge, if they can function as a country and that's what the majority want then so be it.