the beer in a box seems like a good idea for parties. providing draft quality beer in a small package can be convenient for the occasional drinker who wants to have draft available but doesn't want a dedicated kegerator.
but how is it different from the overpriced mini kegs that are already on the market? and how are you supposed to keep it cold unless it is sitting in a fridge? i suppose you could modify a picnic cooler to hold one, or they could market one made specially. (i'm assuming that most beers sold in these are the type that should be served ice cold)