Really???
Will the blackbox tell us the name of the person at the controls when the plane went down???
Will it tell us who was at the controls when the plane was diverted???
Will it tell us what that illegal phone call to the pilot was all about just before taking off???
Will it tell us the name of the mystery woman who bought the SIM card for that phone??
All it is likely to tell is whether the plane ran out of fuel and fell from the sky at that point or whether the pilot sent it into the drink.
The black box will certainly tell us more than we know now which is very little. I hope they find it and this is promising. However even if they have detected the black box they still have little time to locate the plane and that is some deep ocean.
But the CVR only reportedly records only the most recent two hours, so the interesting stuff will likely have been overwritten with engine roar followed by relative quiet and a big splash.