Can't see it, no real feeling for secessionism in current Italian politics.  Everyone-but-everyone is localistic but 99% of the feeling is "campanilismo" = "belltowerism": "our town and its belltower-glorious history-traditions-food-culture-etc is better than the next (nearest, in same province) town and its belltower-etc-etc. The Northern League started as a "fake-separatist" party in the richest northern regions with strong hostility towards southerners - especially local immigrants from southern italy - and a hatred of central government but was basically about northern taxes not going to subsidize depressed areas in the south.  Later went federalist, decided it was content with local governments (city councils, regions) ruling their own little administrative roosts and doing more local-level taxing. Its BIG claim to fame is xenophobic venting - now addressed not against other Italians but against immigrants, africans muslims and roma at the top of the hate-list. It polls around 4.5% nationally these days, in the northern regions its electoral range is from 13-point-something to zero-point-something so not exactly a local majority. Mainly hot air and viciousness.

Dunno about Sud Tirolo?? but only other part of Italy I think does feel it's a different "nation" - with some justification -is Sardinia.. very strong cultural identity. But again, the separatist movement can be fiery (paper bombs) but in serious political terms it's marginal: in the last elections the separatist Sardinian Action Party polled less than 6 percent in Sardinia itself. The "special-status regional autonomy" system has done a lot to decrease centrifugal tensions.

So I don't feel there's any real prospect of a split-up - De Gondi and Melo correct me if I'm wrong, OK?  

"Ignoring moralities is always undesirable, but doing so systematically is really worrisome." Mohammed Khatami