This is the last day to purchase the Programming Windows 6th edition ebook for $20. If you buy it today (or you've already bought it), you'll be able to download the Release Preview ebook tomorrow, and you'll be able to download the final ebook in mid-November at no additional cost. If you wait until tomorrow to buy the ebook, it will cost $30.
Complete details are on the Microsoft Press blog.
Programming Windows, 6th Edition
For just $20, you get: