This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Well, XDoclet 1 continues to work fine (although it doesn't like the generics notation using angle brackets in Java 5 code).
I would guess that version 2 hasn't taken off because the usefulness of JavaDoc-style annotations is much diminished, now that real annotations are available. E.g., Hibernate and EJB (two of the common uses of XDoclet 1) now use annotations, making XDoclet unnecessary.