Understandably, the mainstream media in the UK have been most interested in the French regional elections because of the failure of the National Front to make a really telling breakthrough and seize control of at least one council. But we shouldn't lose sight of the historic result in Corsica, which represents the biggest challenge for decades to the French state's Neanderthal notions of absolute sovereignty. Of the large European states, France is the most backward in that respect, even more so than Spain, which at least allows nations like Catalonia a very substantial measure of autonomy.
Corsican Assembly second round election result (vote shares, changes are from second round in 2010) :
For Corsica 35.3% (-0.4)
French Centre-left 28.5% (-8.1)
French Centre-right 27.1% (-0.6)
National Front 9.1% (n/a)
For Corsica 24 (+9)
French Centre-left 12 (-12)
French Centre-right 11 (-1)
National Front 4 (+4)
It may seem slightly bizarre that the nationalists have achieved victory in spite of their vote edging down slightly, but the explanation is that the National Front didn't make the second round last time, so the presence of the far-right has had an impact on all of the other three parties/alliances - but the nationalists less than the others. In any case, the nationalist vote was split last time between two parties in direct competition with each other.
The constituent parties of the alliance are the Party of the Corsican Nation, which is actually anti-independence but in favour of significantly increased autonomy, and the pro-independence Corsica Libera. It would be interesting to know whether the Party of the Corsican Nation have come under fire for deciding that the most natural alliance is with other civic nationalists, and not with other 'unionists'. It certainly makes perfect sense that they've taken that view, because as long as Corsica Libera have a pragmatic understanding that autonomy within France is the necessary first step towards their goal, the two parties' immediate constitutional priorities coincide entirely.
As you can see, the alliance has fallen just short of an absolute majority (they have 24 seats, and the combined opposition have 27), but there doesn't seem to be much doubt that they will form the new administration. What this result reminds me of most is the SNP's minority victory in 2007, when unionist parties in combination retained an overwhelming majority of the popular vote. The big question now is whether the Corsican nationalists will be able to use their limited power as a springboard to greater things, as the SNP did so successfully.
UPDATE : The UK media's early reporting of the results in mainland France was disappointingly ill-informed. For example, the presenter on the BBC news channel wrongly told viewers that the National Front's vote had "collapsed". In reality, the far-right party achieved its highest ever raw popular vote in any election, and seemed in terms of vote share to be fractionally up on the 27.7% achieved in the first round. The fact that it didn't win outright in any region can be entirely explained by massive tactical voting, and in a few cases by the complete withdrawal of the centre-left from the contest.