In the 5 days since the launch of the Textbooks section of the Apple Book Store, they have sold approximately 350,000 books according to Global Equities Research. They also apparently gave away 90,000 plus copies of the iBooks Author software for textbook production. If these numbers and trends continue, Apple could well have the largest book store sales in the world within a matter of weeks instead of the normal years that it took Amazon to get to the top.
There are no official numbers from Apple yet but if the textbook sales are extremely successful, it is highly likely that they will use the numbers as part of their presentation come time for release of the iPad 3. That event is expected within the month, yet again, no official word of the event has been sent by Apple inc.