Nvidia announced that it will end support for GeForce graphics card users using 32-bit versions of operating systems before the end of this year.
Nvidia has announced that the 390. xx driver update for GeForce graphics cards will be the last one to support 32-bit operating systems. From then on, the "greeners" will optimize the controllers exclusively for 64-bit systems. Nvidia has announced that she will only ensure security improvements until January 2019.
Nvidia's small "revolution" will affect Windows, Linux and Mac OS X owners. The latter don't have to worry if they use Mac OS X Lion 10.7 or later, because all later versions are 64-bit.
It seems that only a handful of players are using 32-bit versions of the systems and hardly anyone will really care about Nvidia's new policy. According to Steam's statistics, 1.98% of Valve's platform users currently use 32-bit operating systems. Holders of Nvidia graphics cards probably account for about 80% of this group.