For example, the novel would not have been possible as an artform without the printing press. Photography and cinema as an artform would not have been possible without the camera and movie camera. Likewise, interactive art will be the artform which will arise out of the digital age, from computers. It's coming has been foreseen by artists for many decades now - mainly seen in attempts to graft its unique qualities clumsily onto other forms: interactive theatre, installation art, interactive paintings, hypertext literature...etc. I believe these types of work are all approximations, prophetic visions of what is to come.
Every medium of art has its own unique quality, something it does better than any other art form. Drama is best at exploring interpersonal relationships among people. The novel is best at exploring the mind and consciousness of a person. Cinema is best at exploring actions and the passage of time.
Likewise interactive art has its own unique quality, something it explores better than any other artform - that is choice.