One piece of info the book does give is confirm suspicions that Darth Plagueis was Darth Sidious's master, meaning that Sidious was the apprentice in the story he told at the opera.

As for the idea of Anakin being created through the efforts of Darth Plagueis, that is a /very/ interesting idea. Which would mean that Anakin was created through the Dark Side, which would mean ... what?