All of my steam games launch just fine without an internet connection, at least.
I think what people are missing out on when looking at the new distribution model, is that it makes passing on the data disc a trivial concern. You can just dump it to your console and then give it to a friend, who can play it in trial mode(or full mode with your account), and if he likes it, he can buy it and rip it straight to his console, and so on. Making the disc unnecessary will only encourage people to share.
