Yes, the mentions of IO.js in the book should mention that it was merged back into Node.js. Out of curiosity which chapter were you looking at? I will check the MEAP and make sure that it has the latest chapter versions.
Just the Welcome before Chapter 1. Why not just remove the references to IO.js? And explain Node.js.
Ah, the welcome bit, yes that was written a while back. I will get round to updating that now.