Rita Mulcahy's PMP Exam Prep, Sixth Edition is available now. The list price is USD 99.00 (plus $10 S&H). Along with the book, the upgraded PMP Fastrack Exam Simulator and PMP Hot Topics Flashcards have also been launched.
The book is only available on Rita's website. It's not on Amazon yet. If you want to purchase it at a discounted price, you might want to wait till it is available on Amazon. The price on Amazon will definitely be at least 25% less than the list price.
UPDATE (June 17, 2009): The book is available on Amazon now. It's temporarily out of stock but you can still place your order.