"Television" watched via the internet e.g. YouTube, Hulu, Myspace Video etc.
"You need to get off the computer, that intervision will rot your mind!"
Its a noun used to describe the internet and the television. Usually used to describe a popular video or something along those lines.
Guy 1: Hey have you heard "Chocolate Rain" by Tay Zonday?
Guy 2: Of course I have! Everyone has heard that song, its all over the intervision.