I'm running 1.33 now. As far as I can tell the only thing it changed is the addition of a pop-up screen with a shopping cart icon that appears when you navigate to the Google book store. The message is the same as before, instructing you to got to Google Play on your computer to purchase books and that they will be available on your device. So same message as 1.32 but in a pop up window instead of a text page.
Not sure why they bothered.