If you want to find out all the new goodies Android's newest upcoming OS, codenamed Gingerbread, is going to bring, you may want to ask Satya Komatineni, Sayed Hashimi, and Dave MacLean. These 3 writers are the co-authors of the Pro Android book series, and, thanks to a tip from @brodduncan, we now know they've definitely been playing with Gingerbread, likely for quite a while.
The new 3rd edition of Pro Android, which recently showed up on Amazon, mentions the Gingerbread SDK in its description:
Pro Android 3 shows you how to build real-world and fun mobile applications using the new Android SDK, codename "Gingerbread."
Learn what’s new with Gingerbread: improved UI across all Android platforms, integration with WebM, the latest Flash integration techniques, and more
The above confirms our earlier suspicions of user interface improvements that Gingerbread is bound to bring as well as reaffirms the WebM integration that Google promised at Google I/O this year.