I've seen this discussion show up in a number of venues lately. I'm not at all surprised about the trend as I've been using Steam for a few years now. I expect they will take a similar path and continue to sell physical medium with keys to tie the game to an account, and do staged downloads using encrypted data which is unlocked at release time. The biggest content for games is really art assets, and much of that work is done months ahead of release and unlikely to change, while fine tuning and game logic (binaries) are small enough that staging downloads in tiers should be easy. There is also the system Blizzard is using for World of Warcraft where the game can stream content down while playing. Most of these publishers/developers already have pretty good grasps on what capabilities are at their disposal thanks to the DLC model they have now, they will just be going an order of magnitude larger on the downloads. I wonder how many will also attempt to leverage P2P models as well to assist CDNs, cheaper for them and maybe even a revenue generator for ISPs charging for transfer overages.