Dragon launch aborted after engine start. Initial reports are that engine number 5 had a high chamber pressure. Unfortunately, since they were launching for a specific window to reach the ISS, they couldn’t do one of those patented SpaceX turnarounds and try again a little later. I believe I heard the next opportunity is in 3 days. More info at Spaceflightnow.
Update: It was interesting that the NASA commentator actually said “Liftoff!” before engine cutoff. He then corrected himself to say that the liftoff light never came on.