According to some leaked screenshots and descriptions, Apple's iBooks app for iPad, iPod touch, and iPhone will be getting an update in the near future that includes "collections", along with PDF printing and emailing.
Collections are similar to folders. You will be able to make groups of books and PDF's that are accessible via the new "collections" button as well as from your bookshelf. User-created collections are completely customizable, but the the two default collections, Books and PDF's, are not.
In addition to collections, the new iBooks update will have the option to email PDF's and print PDF's with AirPrint. You will be unable to print or email books, however. (That makes sense for purchased books but hopefully non-protected ePub books will get print and email functionality at some point.)
There is no word on when we can expect to see this update, but we're betting it'll make an appearance at the rumored Apple event in December.
Who's looking forward to this update? What collections do you plan to create?