Very interesting. It probably compresses game files down and then uncompresses them as the game is launched. It'll probably come with 3-5 minute "Please wait while we prepare your game..." message or something. But, essentially, would allow you to store your games without having to download them again, but there would be some wait time before they launch... Or maybe give you the intro sections that you can play while the game is installing (loading menus, etc). Probably wouldn't be useful for a game that you launch every couple weeks or once a month, but maybe if you have a bunch of archived games that you don't usually play but don't want to remove from the HDD completely, could be useful. Like, I still have Forza 5 installed, or w/e, which I haven't played in years, but I still leave on there in case one day I get an itch... Which hasn't happened in ages, but still. That would be a candidate for me to compress/shrink.
Looks like a pretty early feature though and something sometime off... Especially that 'leftover addons' thing.
I kinda wish that you could opt out of language packs for games. I'm never going to play a game in any other language than English, and I'm not sure how much space a textual language pack takes up (probably almost nothing), but if there's voice over that gets translated, that would amount to a lot. They're automatically included which is good for people in other regions/languages, but it might be something they could offer a toggle for, like:
[X] Make [English] my Default Language in Games
[X] Download Alternative Languages on Demand (When Available)
And, of course, [English] would be an option, versus German, Japanese, Spanish, etc.
