I have to say, I am intrigued about PlayStation Now / Gakai on a mere technology level. Sure, it's just a remote-play feature on a "internet" scale, but IMO, there are some other hurdles I see that I will be quite interested to see how they solve.
For one, how will the solution be sold? Will you have an account, possibly your PSN-id that is linked to the service? And where will you save your progress? I would assume, this would happen in the "cloud", as there wouldn't be much sense to copy data to a local destination and back again when needed.
Also, what will happen once your internet dies on you and you are in the middle of a game? How will it handle the games progress and your session? Would it be easy to re-connect and if yes, how long would that session stay open for you? Would there be some mechanic to perhaps save the state of the game that it could be resumed, even after the session was force-closed?
Then of course, there's the whole issue with latency. I really can't imagine myself wanting such a service for this very reason. Perhaps as a way to demo games, but when I think back at some of the most memorable PS3 times I've had, I really don't think I would want to replay them through a highly compressed feed with added latency (even if consistent).
Maybe technology has progressed quite far on these grounds, but I am somewhat fearful of Sony investing large sums of money into a technology that is inherently flawed. Flawed in the sense that while it might be doable and workable for many games, it won't be for others - and thus, people will either dismiss it and not use it at all.
I guess I would rather buy an expensive add-on with shrinked PS3 in it (even if it's $100) that I could connect to my PSx to re-play by old purchased games. In that sense, I actually thought the ability to rebuy old PSone classics on PSN was actually a good idea and had more potential than some complicated streaming service that relies on large PS3-server-farms that may go unused.