I don't think he was implying that; he was saying that there needs to be a book "Programming in Rust" written by someone outside the Rust projects, e.g. like Dave Thomas and Andy Hunt did with the Pickaxe book for Ruby back in the early 2000s.

Jim is outside the Rust project, other than working for the same employer as many of the Rust developers.

And I think pcwalton is saying that Jim Blandy is very much from outside the Rust project, and therefore satisfies that criterion. :)

Then I guess the OP had another definition of "book" in mind. However, I'll say this: if Jim wants to write a complete book on Rust, I'd love to buy it. I'm more than halfway through his report and it has exactly the tone that I'm looking for in a programming book: clear, logical progression, to the point and no excessive humour that some books suffer from (I'm reading a book on Go (the game) at the moment and every paragraph contains a self-deprecating joke. It gets old after 2 or 3.)

To expand on steveklabnik's sibling comment, Jim Blandy's is writing a complete book on Rust, which will be published by O'Reilly, and is aiming for release by the end of the year. :)