One of the entries I judged for Game Chef last year was presented by video (recalling the theme – there is no book, this fits well).

Video does face the challenge that you mentioned, but it does have the benifit of being able to visually show how some mechanics can work.  It can be accessible to different audiences of course.  It also can be harder to reference in play.

Yeah, I think it can be done quite effectively (I’m at work, so I can’t comment how Brent Newhall did here, because I can’t watch the video), but it may limit what you can do with the game, and it may open up other options that might not have worked as well in print.