At this point, it's safe to say that the explosion on the Vermilion platform in the Gulf of Mexico yesterday won't be another BP disaster. The AP has a handy comparison of the two accidents. And, after talking to a few people about this, here's some more context.
BP's Deepwater Horizon platform, recall, was a drilling rig, boring down and developing a well that was 5,000 feet below sea level. By contrast, Mariner Energy's Vermilion platform was operating in shallower water—340 feet—and it isn't a drilling rig. It's a production platform that moves oil and gas from seven already-developed wells to pipelines.
As such, any moratorium on drilling wouldn't have affected the Vermilion platform; the wells were already drilled. And the explosion wasn't a drilling accident—it appears to have been the sort of industrial fire that can happen at any number of oil and gas facilities (including onshore facilities). The Vermilion platform didn't have a blowout preventer because, again, it wasn't engaged in offshore drilling. Instead it had safety valves to shut off the oil and gas in the event of an accident. According to Mariner Energy, those valves were closed in time, preventing hydrocarbons from leaking out.
Now, granted, even if the Vermilion explosion wasn't directly related to drilling, that doesn't mean it's irrelevant to the broader debate. It's still very much true that oil and gas production carries all sorts of dangers and risks. Aside from BP-style drilling blowouts, there are pipeline spills, refinery explosions, and platform fires to worry about. These things do happen, and they count as part of the cost of our fossil-fuel dependency.