As a part of or continued work to produce solid documentation for Maven, we've decided to spin off the m2eclipse chapter from Maven: The Definitive Guide in a new book: Developing with Eclipse and Maven. As we prepare to expand all three of our current books, we decided that smaller, more focused titles are going to be a better platform for future documentation efforts. The great thing about an online book is that it is flexible enough to evolve over time. It my opinion that, even though books are moving toward a digital-only experience, books that grow larger a few hundred pages don't scale well. For starters, they are difficult to print and navigate, but I also think that a 100 chapter behemoth of a book lacks focus. Even as PDFs, I like my books to be between 100-300 pages.
Book "bifurcation" is not something that a traditional publisher knows how to handle, books are assigned ISBN numbers and it isn't common for a book to replicate itself in such a manner only months after printing. With digital, online books, it's easy - split the source, create another project.
This isn't an announcement of new content, just an announcement that the structure changed a bit. You can read Developing with Eclipse and Maven online. Expect this book to change very rapidly over the next few weeks.