There is no one language to rule them all. You can write a comercial quality game in pretty much any language that you want. Of course the artical says in the next three years. Well the two next gen consoles have been announced and I'm fairly certain that the xbone and the ps4 currently require development to be done in C++ (not so much as require but probably the only tools currently available are in C++). On the PC it may be different. It may be that people even focus on web technologies in the future.
If you want to know which language to learn then there are a few different types of language that would be good to know:
A C variant language: C / C++/ D / Java / C#
A Functional Language: Haskell / Erlang / Scala / F#
A Lisp Variant: Common Lisp / Scheme / Clojure
A High level scripting language: Javascript / Go / Dart / Lua
A Low Level Assembly Language: x86 / Mips / Arm (maybe do two of these a RISC Arm and a CISC x86 for comparison)
Not saying you should be a guru in all or even any of them. But a working knowledge of each of the different styles of programming and their pros and cons will help you when it comes to problem solving and algorithm design which is the real bread and butter of programming.