Bloomsbury says it's counting on a new 3-book set relating to 'Harry Potter'

A new article from Reuters reporting a drastic increase in ebook sales due to the recent release of the Potter series and boost in overall profits for parent company Bloomsbury, also mentioned something that may be of interest to Potter fans:

Bloomsbury, the publisher of the "Harry Potter" series by author JK Rowling, also said it was counting on a new Rowling three-book box set tied into the Potter series, and a non-fiction account of spies in World War II to support sales in the coming year.

While we do not know what this "three-book set" is referring to, we are certainly intriqued by this news article.

What do you think this means? Let us know in the comments below.