Poland is… being repressed. Prussia will end up ceding the Posen area to Russia at the Congress of Stockholm on the grounds that they can control it better. What Prussia gets in return… well, I'll get to that.
I've been wondering about Hungary. It's still a part of the Austrian Empire, but since Austrian influence is rising in Bohemia, Saxony, Baden and Württemberg at the same time as the empire loses its Italian possessions, the empire is becoming more and more German-centered. Conflict potential very high.
Wait, all of Posen? Assuming Russia rule in Poland develops fairly similarly, that's a huge boost in territory and manpower to any potential rebellion in the future, especially is Prussia/Germany has no qualms about supporting it to a give Russia a black eye.
Well, a more explicitly German empire, especially one with the German population to back it up, is probably going to drive the Magyar aristocracy absolutely mad.