I believe there is some misleading information in that article. The maximum of 24FPS is for watching 3D movies. When a 3D capable Blu-Ray player plays back a 3D movie, the BR player transmits the video signal to an HDTV at 48Hz instead of the normal 60Hz. Each Hz represents 1 frame so in 48Hz mode 48 frames are sent to the HDTV, in 60Hz mode (regular non 3D movie) 60 frames are sent to the HDTV.
48Hz equates to 24 frames because 24 frames are sent to each eye. Your brain processes the two separate frames from each eye to create the impression that you are seeing a 3D movie.
While 60Hz mode means the BR player is sending 60 frames per second to the HDTV, that does not mean you are actually watching a movie at 60 FPS. Movies in the US have a frame rate of 23.978 per second. A process called 3:2 pulldown or inverse telecine is used to "cut out" the excess duplicate frames so that the movie is played back at 23.978 FPS. TV shows are recorded at 30 FPS, so dividing the video signal in half will result in the HDTV to correctly display 30 FPS.
As for playing games, HDMI is limited to 60Hz or a maximum of 60FPS on a "normal" monitor. For 120Hz monitors HDMI is limited to 120Hz or a maximum of 120 FPS (assuming your graphics card can pump out that many frames) when playing in 2D mode. All 3D monitors are 120Hz so maximum performance you can get is 60 FPS when playing 3D games. Again 60 frames per eye so that the brain will receive two frames at a time (one from each eye) to fooling into thinking you are seeing something in 3D.