I'm torn between buying it or not, since I'm now experiencing the benefit of switching into a digital game without the need to get up my seat. However, I still prefer physical, tangible copies of games, especially if those games are AAA. If I buy a digital game, it has to be a game that's a few years old and inexpensive (less than $30).
I suppose that a digital-only console should give us the choices to store the game on that console on a massive HDD and/or to stream the game from their service. I just don't think that could be viable nowadays as not everyone has internet above 20Mb upload, which is a pretty good minimum. Also, downloading an entire 50GB game into a limited and slow HDD would be more of a nuisance than a benefit, since you'll need even more disk space for all games, which will get even bigger as time passes. And if you want to redownload a game you already have on your library, you'll have to wait a couple of hours to do so.
The idea won't just work unless there's some good economically viable technology backing it.