We've already seen some rumors about what Apple has in store for its education-minded announcement in New York City tomorrow, and now Bloomberg is out with a report of its own that backs up some of those earlier rumblings and offers a few new details. Citing two people with knowledge of the announcement, it says that the main focus of the event will be a set of tools that will "make it easier to publish interactive textbooks and other digital educational content." That not only includes tools for the big textbook publishers, but self-publishers as well -- Bloomberg gives the example of teachers p