Update (11:46 Pacific time): Spacecraft separation! New Horizons is on its way! It'll pass the Moon's distance in about 9 hours (it took Apollo 3 days), and then it's next stop: Jupiter. Well, not stop actually, it'll pass Jupiter pretty quickly, and gain a huge amount of velocity from the giant planet, speeding it up more and shortening the trip to Pluto by several years.
Update (11:42 Pacific time): MECO! Main Engine CutOff. New Horizons is over the Indian Ocean, and everything looks great.
Update (11:34 Pacific time): the Centaur upper stage is firing now, and everything looks good.
The launch of the New Horizons mission was successful! The Atlas took off at 19:00 Universal time January 19, 2006, and the launch was clean. The Centaur upper stage rocket has fired, and currently the whole shebang is coasting for about 19 minutes. Then it will fire again, breaking orbit, and the probe will be on its way to Pluto via Jupiter. I'll continue to post updates as I hear them.