European Federalism

I know this is a question that is discussed all the time but I would like to see this community going so I will try to create a discussion here.

So what I mean is not only about language used at level of European institutions, but more about setting a standard for European citizens. While English is closest to the standard "European" language nowadays, as far as I know there is a huge difference between the amount of English speakers in different European countries, not to even mention the level of fluency of those who can speak English. How do you think this problem will/should be solved? Further emphasis on teaching/learning English? Eventually, do you think finding different "lingua franca" for European Union is possible? Also, what do you think the attitude of member states will be to potentially going "bilingual" in the future?