Apparently it launched yesterday. Impressions so far
seem to be great. If you have a Mac or a PC with bad
hardware (netbook), it's supposed to be pretty awesome.
They're also releasing a little box and controller so you
can play the PC games through your television.
The community features also sound pretty awesome (you
can jump in and watch others play their games). The only
thing that bothers me is the price. $15* / month for access
to the service; plus you still have to buy the games. You
can also rent some games ($6 for 3 days or so), which
sounds pretty awesome.
Right now it apparently streams at 720p; but I read they're
hoping to get it to 1080p by next March.
Here's a video of it in action uploaded by someone who
just activated their account.
YouTube - showing off ONlive
Another review from a user
This is only available in the US, as it required OnLive to
set up a huge infrastructure across the country
*If you register as a "founder," the first 12 months is
free, and the second year is only $5 / month. If you're
not selected as a "founder" (registration ends in July),
then it's normally $14.95/ month. $5 / month seems
like a good price.