I still think digital distribution and/or streaming is a good 10-15 years off. The internet providers in the US either cap their download speeds/usage for people, or the speeds aren't fast to the point where you can download huge games online. Let's take the recently offered selection on PSN+ during E3 week. Ratchet & Clank: All 4 One is a whopping 14GB download on PSN, and it took me a good couple hours to download it (I feel I have a decent-good internet connection). Let's not mention that I have a 320GB HDD in my PS3, so that would leave me with a lot less space. I could have went to a store and gotten the game (I wouldn't have because it was free, but that's besides the point), and came home to play it in a matter of less than an hour.
I think we won't see something like this until the US companies get to the speed of some other countries, and even then, it might not completely negate retail copies of games. While digital distribution is a great thing for smaller companies like NIS America, or even smaller developers, I wouldn't want to be buying every single game through a digital service. Unless a game is either free (or a huge discount) or only offered through digital means, I will most likely be buying the retail version and I never want that going away.
