Yes, you heard it right! George R. R. Martin confirmed on his blog Not a Blog that A Dance with Dragons
will be released by Bantam Books on the 29th of October simultaneously in Mass Market and Paperback. As he says himself
This was done largely at the request of the bookstores. The hardcover was still selling strongly (still is, actually), so they wanted the paperback delayed.
George R.R Martin 2013
He has also confirmed that a The Winds of Winter chapter will be published along with the paperback (but at this stage he cannot remember which one!)
Also in a surprise announcement in this blog post, he has confirmed the publication of a BRAND NEW booklet written by him to be in bookstores by Christmas called The Wit & Wisdom of Tyrion Lannister
More information is yet to be known about this new book.
Comment below about what you think of this exciting news!