According to Borders, Barnes & Noble, and Amazon, there will be a movie tie-in edition of Sarah Blakley-Cartwright's novel available in March.
The new tie-in edition will be out March 16th. The page count for this edition appears to be the same as the one currently in stores, so no word yet on whether this edition will contain the illusive ending.
UPDATE: I received the book in the mail today. The contents are the same as the previous edition, just a new cover.