More like Europe in space (more socialist/democratic) and I wouldn't mind it - but then I guess I'm biased, as a European (and I half-seriously fly the flag of United Federation of Planets).

Still, I don't think we can face planetary-scale challenges much longer as a bunch of competing nations; some form of global governance will be necessary for humanity to move forward.

As for culture difference, this may be unpopular opinion, but I do hope things will homogenize further over time. The driving aspect towards cultural unification even today is that people copy what works.