Is the BP Gusher Unstoppable?

From a comment on The Oil Drum:

Contrary to what most of us would think as logical to stop the oil mess, actually opening up the gushing well and making it gush more became direction BP took after confirming that there was a leak. In fact if you note their actions, that should become clear. They have shifted from stopping or restricting the gusher to opening it up and catching it. This only makes sense if they want to relieve pressure at the leak hidden down below the seabed…..and that sort of leak is one of the most dangerous and potentially damaging kind of leak there could be. It is also inaccessible which compounds our problems. There is no way to stop that leak from above, all they can do is relieve the pressure on it and the only way to do that right now is to open up the nozzle above and gush more oil into the gulf and hopefully catch it, which they have done, they just neglected to tell us why, gee thanks.