What I'm hoping to see at this front, since install sizes are bloating, that the installers/configuring becomes slightly more advanced.
When I install a game I want to be able to choose the following at install-time:
Texture Packs (main blobs that takes up a lot of space - why download 50GB if you need the 10GB version)
Language Packs
Voice/Audio Packs
Mode Packs (Single Player Campaigns, Multi player, maps)
This way you can take a game that currently cost say 80GB for everyone to average out 30GB to 50GB for most players. On the low end the same game needs to work at 10GB and at the high end can consume the whole 80GB for the person with hardware that can take it. Obviously for console players, they just want to play and get on with it and maybe wont enjoy the choices mentioned above, but PC and tweakers/benchmarkers/modders should enjoy it.