In 1996, The Economist wrote “English might now be impregnably established as the world standard language: an intrinsic part of the global communications revolution” . In the same year, an article titled “World Wide Web: Three English Words” in the New York Times let us know that “if you want to take full advantage of the Internet, there is only one way to do it: learn English.” And indeed, in the late 90s, 80% of online information was in English, a large fraction given that only an estimated 8% of the people in the world are native English speakers. However, by 2002, the fraction of English websites had dropped to less than 50%, by 2005 to about 1/3 , and in 2008 English had dropped to 29.4%, followed by 18.9% Chinese and 8.5% Spanish. Today the web thus reflects the diversity of languages in the world much more accurately than a decade ago.
The idea that English would overtake the world through its dominance on the Internet therefore was wrong. Nevertheless, small countries whose languages are not very widely used have a too small market share to synchronize movies or translate books into the local language (eg the Netherlands), which means that growing up in such a country people will learn foreign languages very early or miss a big part of what the world is talking about. It isn't particularly representative, but I know several couples with differing native languages who mostly communicate in English, meaning their children do (or will) grow up trilingual. And how I envy them for the ease with which they will be able to travel around the globe.
All in all, despite the fact that people do prefer their mother tongue, different languages pose a difficulty for communication, an obstacle that requires effort to overcome. Wouldn't it just be so much easier if we'd all speak the same language? If I crank forwards the clock for some thousands years - provided that mankind still exists and the level of connectivity remains or increases - I thus think we will settle down into one common language, which will very likely be none of the languages we speak today but some aggregate of present languages. Certainly, there will be interest groups for the preservation of language diversity. If they have spent all their donations setting up their website in 50 different languages, they will realize fighting against a trend towards simplicity is futile.
When it comes to traditions however, the situation is different. May that be rituals, festivities or recipes - though these do compete with each other for our time and taste, I see no strong reason for this diversity to dwindle. You might prefer to stick to people who share your traditions, but this is much more your private business than a language you need to get through your daily live. Again jumping ahead some thousand years, I thus don't think these differences will be erased, for much the same reason that interior design differs from one house to the next. I am undecided about cultural differences, as these fall somewhere between communication and tradition.
What do you think?
I have to admit though, there are advantages to not being a native speaker. If I want to get rid of solicitors, I conveniently forget I speak English.
 “The Coming Global Tongue,” The Economist, 21 December 1996.
 Numbers from “Who Controls the Internet?” by Goldstein and Wu