NASA will literally roll out the new Ares I-X rocket on October 19. It will roll from the Vehicle Assembly Building to launch pad 39B on that date, and prep for an October 27 launch. The launch window is from 08:00 - 12:00 EDT (12:00 - 16:00 UTC).
That's a tad early for me to wake up to live tweet it (I'm two hours earlier) but if the launch holds off a couple of hours I'll see what I can do. Remember too it'll be covered on NASA TV.
The Ares I-X is not NASA's final rocket assembly that will take humans back into space in the post-Shuttle era; it's a test vehicle to check out some of the hardware and procedures that will be used in the full-up Ares I rocket. And NASA plans on building the larger and more powerful Ares V, which is what will return us to the Moon, assuming all goes according to the current plan.