Sorry, let me rephrase my question: ITTL, Maximilian attempts to federalise the Austrian Empire by turning it into the Empire of Central Europe (working title; any better suggestions), which is basically an earlier version of the planned United States of Greater Austria. But given that his OTL attempts at compromise between two vastly different groups has been met with less than success (see: the Mexican Empire), would it just end up falling apart as both the Austrian aristocrats, pissed at their sudden loss of power, and the Nationalists, pissed by the fact that they feel that not enough was given to them, start railing for his blood? Or is nationalism early enough for it to be satisfied with local autonomy?[/QUOTE]
In my very humble and not incredibly informed opinion, for anything like this to sort of work he would need a _massive_ level of democratization. Think about a universal male suffrage sort of thing.
The point is that nationalism did not emerge uniformly among ethnic groups of the Empire. It was well-developed among Italians, Germans, Hungarians and Poles, fairly active among Czechs and Croats, embryonic (but already underway) for most of the other groups such as Slovenes, Romanians, Serbs, Slovaks, and "Ukrainians" (quote marks because they were generally called Ruthenians at that point and often considered as somewhat different from Ukrainians in the Russian Empire, though it was more complicated). And I think there were other national movements as well, though the above were by far the most significant.
So, social developments may make some regions more or less restive relative to OTL. A peaceful resolution of the Italian issue can have all sort of consequences, either inducing other national groups to try and force their views through the center, Ausgleich-like, or having them consider the untried might of the Austrian army (undefeated here, and probably reformed after a less-than-expected-though-still-succesful performance in the *Crimean War).