The Google Play Books update received an update this afternoon to version 2.7.25, expanding support for several features, as well implementing new functionality for others. Here's the changelog:

What's in this version:

You can now listen to most flowing text books using the "Read aloud" feature.
You can now pinch-zoom or double-tap-zoom in all books.
All text editing features are available for notes.
Personalized recommendations are shown at the end of your library and at the end of the books.
Numerous bug fixes and performance enhancements are included.

While this isn't exactly a massive overhaul, expanded support for things like pinch-to-zoom / double-tap zoom, read aloud mode, and note editing are objective improvements to the app. Personalized recommendations at the end of your library and books, well, let's call that one a "neutral." The requisite bug fixes and performance tweaks are packed in to this update as well, which you can grab on the Play Store now.

Google Play Books & Audiobooks
Google Play Books & Audiobooks