UPDATE: GLAST has launched, and is in orbit! The solar arrays have deployed, and everything looks great. Phew! It's been a long road to space, but it's finally there. It'll be some days before the scientific instruments are switched on, but I'll have more news as it develops -- including the new name for GLAST.
GLAST may yet launch today, at 12:05 Eastern (15 minutes from now as I write this). I found a live video feed, and I'm Twittering it. I'm streaming NASA live and chatting on my UStream page; go there and join the fun!