The trains run at ten minute intervals (as of September 14th, when they added ten pairs of trains to the service) between 6:30AM and 10PM, and cost 69 yuan (about ten dollars) one-way in first class. The new service has cut travel time from 70 minutes to 30.
Photos of train and brand new saucer-shaped Beijing South Station in the CNReviews blog posts Part 1 and Part 2.
I very much want to ride this.
*There's already a 431 km/h (268 mph) maglev connecting Shanghai Pudong Airport with a somewhat inconvenient outlying station on the Shanghai Metro. Of course, I want to ride that, too.