You can make a similar list for Latin though; the Romance languages are (by definition) descended from it; that's Spanish, French, Italian and Portugese, and English and German are heavily influenced by it. That's a significant majority of the score of the top ten languages from the article, so you can argue that by their standards Latin is more significant, even though it's no longer really a living language in its own right.
Good point; I thought the article missed out on analysis about indirect influence by a language through influencing neighbouring languages. Would've been nice have read about Latin's influence on other languages rather than have it being a mere footnote.
It really depends on how you define a language and a speaker. I have heard estimates that English is currently the most spoken language of all time. (at least on earth). With over half of the worlds population being familiar with at least a few words, 1.8 billion people with basic competency, and a steady trend of English words being adopted into most other living languages.
The winner of the "Top Language of 100 AD" should go to Chinese circa 100 A.D.
http://en.wikipedia.org/wiki/Sino-Xenic
The following languages are heavily influenced by written chinese:
Korean http://en.wikipedia.org/wiki/Hanja
Japanese http://en.wikipedia.org/wiki/Kanji
Vietnamese http://en.wikipedia.org/wiki/Vietnamese_language
As well as a variety of other languages (though the regions where they are from are now considered part of China):
http://en.wikipedia.org/wiki/Chinese_characters#Other_langua...
Moderately influenced:
Mongolian http://en.wikipedia.org/wiki/Mongolian_language
Thai http://en.wikipedia.org/wiki/Thai_language
Here is a picture of Han China and Roman Empire circa 100 A.D.
http://www.roman-empire.net/maps/empire/extent/rome-china-co...
Written Chinese still dominate its slice of the world.
While not all chinese are conversant with Standard Mandarin, (I am not), almost all of them can read and write chinese.