And tomorrows language is mandarin. Let's not write off that 1.1B speakers. With the rate China is expanding its influence in the world, I wouldn't be surprised if in 100 years not speaking mandarin wouldn't look a bit odd.
But I think you were downvoted for the wrong reasons, since otherwise the argument is fairly sound. Chinese influence is continually increasing world-wide. It's mainly the writing system that prevents a wider spreading of Mandarin, and the Chinese cannot give it up because it unifies their nation. Another possible scenario is that other languages of China die out even more quickly than they already do now, thus paving the way to full mutual comprehensibility via Mandarin, which would then allow a drastic reform of the writing system. However, this seems unlikely to occur within the next 100 years.