6 Hours to closest approach...
Although there's a 4 and a half hour light delay to Pluto, we won't get live updates... in fact, it'll be more than 12 hours until the first telemetry confirms we even survived passage through the orbital plane (at 30K mph/49K kph impact with even a pebble the size of a grain of rice could mean loss of spacecraft... NASA estimated the odds at about 1 in 10 000... fingers crossed).
To save mass and complexity, the sensor packages aren't on moving arms or platform... the whole spacecraft has to turn to point them, so it can't collect and send data at the same time. Most of the flyby is spent with various instruments rotating pointing at Pluto or Charon (a wee bit at Nix, Hydra, etc). IIRC, the only times the main antenna is pointing at Earth during closest approach are actually when it is receiving
signals from the Deep Space Network to calibrate the REX experiments, measuring the atmospheric composition and density of Pluto and/or Charon.
Closest approach is 7:49AM EDT
We won't start getting data back until many hours after closest approach... in fact, there will be sooo
much data, some instruments will only send brief headlines/synopses... the full data download may take weeks
Telemetry download approximately 9PM EDT
NASA TV has press conference scheduled about 9:15PM to confirm high-fiving scientists (fingers crossed)
Close-up images and comprehensive data to be released starting tomorrow
For more details on the schedule of activities, see http://pluto.jhuapl.edu/Mission/The-Flyby.php
Follow the path of the spacecraft in coming days in real time with a visualization of the actual trajectory data, using NASA’s online Eyes on Pluto. (<-Sadly only available for Mac or PC, not mobile devices)