I'm split on the importance of box art for video games. It has its disadvantages, and a few advantages, over advertising and distribution on the Internet.
On one hand, I think that box art is a disastrously bad thing for the environment. The plastic, the unnecessary extra toys that end up in refuse, the fact that plastic itself is a product of the very harmful product of oil... These things all make it an ethically unsound practice to release every big new game with huge box art and collector's edition packaging with extra Happy Meal-style toys.
On the other hand, I prefer physical distribution over digital any day. The fact is, a disc is far more reliable than a section of data on your hard drive, or on a server's hard drive for that matter. There is no way to pretend that current trends towards digital distribution are going to lead to a more environmentally friendly world, since running servers constantly, and all the electricity and production that goes into that, is a very exorbitant process. Physical distribution is also more consistently marketable in real terms than advertising and distributing online, since the amount of sales you get per hit on an ad can be poor indeed.
If only there would be a way to make a game's packaging look as sexy as the big release ones do, without hitting the environment. This would be like taking a third option, and avoiding the excess of the other two. Hemp game containers and 100% recycled manuals, anyone (or perhaps, 100% green powered Internet services)? But why would we use that idea? After all, it makes much more sense to waste a limited resource on something that will be continually produced until it runs out and we're left without other means of creating it. Right?