It's actually hard to hold when it's almost all the way cooked -- it'll start getting gluey on you if you let it cool off, but could start scorching on the bottom if it's not stirred, and get too runny if you keep adding stock.
I saw a show and Mario Bitali said that risotto isn't finicky in the middle -- so you can cook it part way, cool it down (I think he said he spread it on sheet pans to cool quickly), then can add hot stock and cook it from that point, so you've already got a 10 minute head start.
I've also been to a restaurant where it was only served on the hour and half hour.
(okay, I admit it ... it was on Martha Stewart, about 12 years ago ... I was living in Kentucky, and didn't have cable, so there weren't many options of what to watch in the morning while waiting for the others in my carpool)