<p>I have read through several reviews on Amazon and some books seem outdated.  I am currently using MyEclipse 6.5 which is using Eclipse 3.3.  I'm interested in hearing from people that have experience learning RCP and what reference material they used to get started.</p>

Although I don't have personal experience, a few friends of mine did Eclipse RCP development, and they used the book "
Eclipse Rich Client Platform: Designing, Coding, and Packaging Java(TM) Applications
". They seemed to like it a lot, and I looked it at myself, and it seemed useful. If I was going to do RCP development on Eclipse, I would probably get this book.
To clarify - this book is geared toward Eclipse 3.1, and since I haven't done any RCP development of my own, I'm not sure how much things have changed.