tl;dr Allow games to offer multiple download sizes and rely on streaming for content where needed.

This feature used to be part of Battle.net but it looks like they did away with it. Basically, allow developers to set up different 'completeness' levels to a game's download. This is optional and up to the developer, and may or may not be enabled in the game's betas as well.

If applied to DotA, a minimum-download might just include the game engine, the default map, and hides cosmetics (or streams them in at the start of the game) and disables map skins and the arcade. Then an intermediate one has event files, the game caches the player's active cosmetics (including map stuff), and streams any other player cosmetics as the game starts, holding on to the most popular ones. Finally, the complete version is the full size and has all the cosmetics and such pre-saved for the fastest loading.

Right now this can be approximated using the Steam 'betas' feature, but I feel like this could be a serious feature for allowing developers to easily access new players trying a game by shortening the delay between impulse and ingame. It also means that download loads are reduced for players who uninstall games to try and avoid them but occasionally reinstall to indulge. (Such as myself.)

It's certainly a technical feature and requires the developer to build their game around this content, but I think it could be jury-rigged by extending the DLC system to include these feature levels.

Thanks for the Consideration,
k5