Practical API Design: Confessions of a Java Framework Architect by Jaroslav Tulach
The Definitive Guide to NetBeans Platform by Heiko Böck
Neither of the authors are present at JavaOne, so some of the editors and translators of these books will be available to sign the books instead. If you buy both books at JavaOne, Apress has generously agreed to give you this really cool t-shirt:
See you there!