While the inability of modern (or indeed foreseeable-future) internet connections to deliver disc-quality HD gaming without lag would make a fully-Gaikai PS4 a total non-starter, streaming capability as an augmentation would make it a much healthier prospect as a platform. Don’t want to waste 20 minutes and a whole bunch of hard-drive space downloading a demo that you’ll only play once for about the time it takes it make a cup of tea? Stream that sucker instead.
Don’t have the cash to splash out on a PS4 model with a giant hard-drive? Get a cheaper one, stream your PSN games, and upgrade later. Want the console with the biggest launch line-up next generation? With Gaikai-enabled streaming, the PS4 can have every PS1, PS2, PS3, PSP and Vita game ready to go at the touch of a button.
And let's not forget, if Sony can wangle some dexterous licensing, it could have a raft of PC games ready to go on the PS3 within a year, creating a temporary buffer with which to delay the launch of the PS4 until it can comfortably afford it.
Also, consider Sony’s patchy track record with remote-play. The dream of using your PSP or Vita to continue your PS3 game on the move has been a particular Moby Dick of Sony’s for years, but has never really successfully got off the ground. Now consider that functionality run through a Sony-owned Gaikai network.
You could be playing a game on your PS4. You might be streaming it, or your might be running it locally. You pause. You select ‘Switch to streaming device’. Your PS4 stops running the game, your PSN account fires up your streamed version (with your current save position secured by the cloud, obviously) and starts streaming it directly from a meaty, dedicated Gaikai server to your PSP, Vita, laptop or phone. Without relying on a console to do a server’s job, the system could be smoother, faster, more responsive, and basically work the way Sony has always wanted it to. And with a hell of a lot more receiver devices expanding accessibility across the board. You could even theoretically buy into PS4 without even buying a PS4.
Yes, all the obvious (and warranted) doubts about streaming’s legitimacy as a gaming medium in itself might have you thinking that Sony has dropped a really expensive ball here. And that would be completely understandable. But there is serious potential for real benefit. Those benefits might not shape the PlayStation’s future in the same way that cloud-gaming’s loudest supporters might want to believe, but if played right they could make Gaikai well worth the price tag for Sony.
And anything that's good for the health of PlayStation, either as a specific machine or as an overall gaming brand, is good for us all.