Video games of the future will certainly be far more interactive, social and intelligent.
The games of today generally involve a pre-determined story, which the player can 'complete' by carrying out various missons or tasks in the game.
Virtual reality
The video games of tomorrow will be different. Virtual reality environments coupled with body-sensing controllers (such as far more advanced versions of the Xbox Kinect or Nintendo Wii) will make it possible for the player to completely immerse themselves within the story. These controllers will make gaming a far more 'real' experience than simply operating a character on screen through the use of a handheld device.
Non-linear stories.
Nowadays we are already seeing a shift towards open-world games and non-linear story lines. Games of the future will most certainly make greater use of this kind of story-telling. Every decision the gamer makes will have some sort of knock-on effect on the ending of the game.
Artificial intelligence
Future games will use far more advanced artificial intelligence, maybe even so advanced that a character controlled by the game may behave, act and react almost exactly and intelligently as an actual human being.
One's thing for sure about the video games of the future, they're going to be more real, more interactive and far more addictive!