Instant on is still a factor, maybe not for you and certainly not for me (my home PC runs 24/7), but there's plenty of people who don't leave computers running when not using them, and still would enjoy not having to wait while it boots up.
The biggest use-case I see for the future is as a media centre connected to your TV. Google are already trying to replace computer software with web apps, why not TV software too - think Boxee or any other similar device, but all through web apps. If it took off I think it would be awesome.
Instant on is still a factor, maybe not for you and certainly not for me (my home PC runs 24/7), but there's plenty of people who don't leave computers running when not using them, and still would enjoy not having to wait while it boots up.
The biggest use-case I see for the future is as a media centre connected to your TV. Google are already trying to replace computer software with web apps, why not TV software too - think Boxee or any other similar device, but all through web apps. If it took off I think it would be awesome.