Playing Devil's Advocate here, it sounds as though the only real breakthrough is that the existence of a Will Shakespeare from Stratford has been confirmed, as has his association with the theatre via the reference to him as "the player".

I have yet to read the book itself of course, but this article certainly doesn't provide any details that would prove beyond reasonable doubt that said Will Shakespeare, "player", was the author of the massive oeuvre of genius that has come down to us bearing his name. The existence of William Shakespeare of Stratford has never been in dispute, nor has the fact that he was associated with the theatre - at least insofar as the case for Edward de Vere, Earl of Oxford, as the real author, is concerned.

Perhaps the book itself provides further evidence, but it seems improbable to me that a man who had never left England could have shown such familiarity with foreign locales like Verona - all of which, incidentally, de Vere is known to have visited. Or that he could have the extraordinarily broad knowledge of law, medicine, languages, protocol and court life, etc etc that are evident in the works of Shakespeare.

It doesn't seem to me that the hypothesis that the man from Stratford actually wrote Shakespeare's works has been proven.