It would certainly revive the PC industry, though it hasn't been dead or even dieing I think.
But even more important is that it will bring all the gamers together, consoles and pc's can play against each other, or well at least the ones playing on a PC and the ones playing on a TV (replacing consoles).

I think i all depends on the business models they come up with.

If you still have to buy every game, if you want to play it, then they're kind of stuck in the past.
But they could offer a package, where you pay some amount per month and then you can play every game on their service, and depending on what games are being played the developers get their shear of the monthly fee, much like the Television industry works. That way an indie developer would get as much for the played minute as a big time developer.
It would be all about how many people play your game and how long.