With the PlayStation 3 and PlayStation Portable, you could certainly download quite a few games. With the new PlayStation 4, however, it sounds like digital downloads will be a primary method of distribution. Sony Worldwide Studios boss Shuhei Yoshida told The Guardian that every single PlayStation 4 title will be available digitally.

"PS4 will be similar to PS Vita in that every game will be available as a digital download, and some will also be available as a disc," he said in an interview last week.

And once Sony has a whole library of digital PS4 titles, Yoshida hinted, a subscription service might also be in the cards:

As more and more services and contents become available digitally, we'll have more of an option to create attractive packages. So hypothetically we can look at different models – like a cable TV company. We could have gold, silver or platinum levels of membership, something like that. We can do subscription services when we have more content – especially now that we have the Gaikai technology available. With one subscription you have access to thousands of games – that's our dream.

Gaikai cloud servers could wind up being key to Sony's strategy if the company's serious about digital distribution. While you can already download a bunch of full PS3 titles that normally ship on Blu-ray disc, they can easily top 10GB, with quite a few of them taking up 20GB or more. PlayStation 4 titles could be even larger. Blu-ray has a theoretical capacity of 50GB with a dual-layer disc, and Blu-ray XL fits 100GB. Those games could take a while to download in the United States, unless you live in Kansas City, and take up plenty of hard drive space.

However, with Gaikai's streaming game service and Sony's play-as-you-download tech, you could theoretically enjoy a subscription service without worrying about such things: simply stream or download as many bits as you need while you're playing. That's the dream, anyway.