This is a given, it's going to happen sooner rather than later with the big 3.
What bothers me is this:
1) I don't think we're going to save any money. I see no evidence that now or in the long run we're going to see significantly reduced prices because the "middleman" has been cut out.
2) I like being able to resell items I don't like or am not using any longer. That's gone. That changes ownership significantly, and it is like renting.
3) I don't trust the big 3 (as opposed to the Steam situation where the Windows architecture stays similar) to keep my purchases available or playable to me in the future. The 360 has spotty to crap back library compatibility, the PS3 has taken a dump on arguably the best back catalog of all time, Nintendo just looks for ways to sell me the same games again and again.
4) Outside of Microsoft, I see no real mandate to offer us demos before making digital purchases.
I'm not trying to be debbie downer either, I like the convenience, I hate GameStop, etc. But it's going to change a lot of gaming ownership issues for the worse.