At 10:29am EDT today, Yahoo News reported that BP had successfully stopped the oil leak, but cautioned it was still too early to declare victory. Apparently that caveat was indeed a prudent one, because as of this writing - 1:57pm EDT - the gusher is still going on strong as ever, as seen on the live cam. It does, however, look somewhat muddier than before. BP chief executive Tony Hayward said that it would be at least 24 hours before officials know whether the attempt has been successful.
The company intends to eventually inject cement into the well to permanently seal it. Just how they intend to accomplish this is not certain, since cement's failure to hold back the powerful pressure of the gusher is precisely what caused this disaster in the first place.
The mud-pumping technique being used is explained here on Reuters.
