the thing about the drm check though, is they could have done this exactly like they are currently implementing it with games that can both be purchased in store on a physical disc, as well as on the marketplaces (on psn and xbl).
if you get a digital copy, it's locked to your account.
it you have a physical copy, and you want to install it, install it and it simply checks for the disc in the drive or something (like it does now on xbox360) before you play the game, not phone home every 24 hours.
if you have a physical copy, and you want to install it and NOT have to have the disc in, then they can have a key that ships with it, similar to the online-passes. that way it can only be validated once and installed once.
BUT ... and i do know this is a huge caveat and why they didn't do this, it means if you did install it you could sell the disc or give it to someone. basically you could get 2 copies for the price of one.
me personally, i just wish they kept it how it currently is on ps3/360 - you can buy the disc if you want and if you have the disc version, you can install it but need to have the disc in the drive to play.
then they simply make EVERY game downloadable, and if you want to go that route and download it, then you can, and it's tied to your account and can never be sold or anything, just like it is now.