> by the end of 15th Century Gutenberg’s invention started putting an end to that local Babel Tower

I heard a wonderful radio programme where they discussed the evolution of BBC English - they couldn't call it standard English (as it wasn't) and eventually settled on "RP - received pronunciation", essentially the way English was spoken by "educated people" in the South East of England. They asserted (and played tapes to prove it) that the dialects spoken across Britain could not be understood by people from outside their area (I listened to schoolchildren in Devon and in North East England and it was very difficult to tell what they were saying).

It was only in the last twenty years that today's (modified over time, dialects) were "allowed" on to the airwaves. (The popular dialect for radio DJ's was for several years "mid Atlantic").

So if it took the printing press to encourage standardisation of written English (I can only speak for Britain), it took another invention (the radio) to begin the standardisation of spoken English.

Perhaps in the future, people using whatever the Internet becomes will talk of the days when people all over the world spoke different languages. Who knows?