This is bad news for supporters of a European federal state, but it is not necessarily bad news for supporters of European integration. There is no reason to assume that building a neo-Westphalian state is the only solution for the enhancement of European integration. In particular, there is no need to demonise diversity, overlapping authorities and multiple identities.
Divergence is a normal state of affairs.
All this does not necessarily mean that we are condemned to neo-medievalism. Nor does it mean that there is nothing wrong with the rise of a neo-medieval empire in Europe. Cultural identity and democracy require transparency, simplicity and a sense of belonging to a defined community, and these are difficult to acquire in a highly diversified and open-ended environment. We should, therefore, work hard to mitigate the negative effects of neo-medievalism. In fact, some of Fischer's suggestions could well be employed for this end.