Personally, I think the idea of streaming a game is unimaginably bad.
It's bad enough that digital downloads don't give you a physical copy of the game. Yes, you can usually burn a file to a disk (though the EA store doesn't appear to let you, going by my free ME2 copy). But they also often require their own special patches to be made for updates, or have some downloading program always installed to be able to play, and other such niggling little things. It's not all bad, but it's not as nice as having the physical disc, manual and all that, installing it, and playing without the need for those downloaders. I mean hell, you pay $50-$60 either way, and you'll be saving it to disk too, so why not get an actual physical object with some niceties, right? But streaming games? You don't even get... well, anything.
With OnLive, you pay anywhere from about $7 to $50 for a "Full PlayPass" for a game. You don't get a game, you just get access to it for as long as they have it available on their service. Let me say that again... for as long as they have it available. That's right, they guarantee they'll keep it for a minimum of three years. After that, at any time, you'll have pissed $50 into the wind and have nothing to show for it. Even the EA Store's better than that, and it's a piss-poor substitute for something like Steam or Impulse.
So what happens when streaming servers go down, or services end? The game's gone, the money you forked out's gone, and so's the game. Then to play it, you then have to hope it was also made available elsewhere via DD or a brick and mortar store (i.e. buy it again). Also, don't streaming games require you to be online to play them? And uh, isn't Ubisoft and others getting a load of shit for their "always online to play" stunt? So no online, no game to play? That's not a good thing. And really, what are ISPs going to think about you burning through GBs of data every time you play for a couple of hours? Anyone else think they'll start creating bandwidth caps like some ISPs in the U.S. are already playing with?
Now don't get me wrong. I like Steam. It's a good set up. Impulse is... all right, but they don't give you the ability to break up a big file into DVD-sized parts like Steam, or offer parallel downloads to get games quicker (though you can delete the downloader and still play legally, unlike Steam). But to me, there is no upside, at all, to streaming video games. It's bad enough that the physical discs are slowly being phased out, yet prices aren't dropping. I like getting something tangible when I pay out cash, but I can at least accept it being just a file to save and download as many times as I want so I can play on or offline whenever I choose. Not even getting that with streaming is just ridiculous to me.
Call me old fashioned, but I like the idea of being able to play the game I paid for 20 years down the road... without having to buy it again.