So now launch is postponed until July 4th, 2:38 p.m. Eastern time.
Keep track of NASA's launch plans by reading the Launch Blog
Boy, I hope the launch goes off on the 4th. If it doesn't, I'm probably going to be asked questions about launch (which I have some knowledge about, but I'm studying mission objectives and re-entry like the show producer asked me to).
We'll see how it goes, though.