A lot of those guys know enough to write several books. Unfortunately, most of them don't seem to enjoy writing things for humans to read as much as they enjoy hacking on VMs. :(
Even if he never does, we're lucky to have the source to many of his VMs available :)
Would the dart VM be the place to start? It's the newest and I saw a presentation somewhere where it looked like part of what motivated them to create it was having to deal with so many edge cases in JavaScript. I imagine the source of V8 is probably not going to be that easy to pick up.
Why do we need so many different VMs anyway? Is it it just history and politics? Are, e.g. Python and Ruby so different that, if implementing from scratch today it would make sense for each of them to have its own VM? What about the CLR vs the JVM: are their respective functions so different that it would make sense for both of them to exist if not for the need for Oracle and Microsoft to maintain mutual incompatibility?
I would pay three times as much for a book by Mike Pall. With all due respect to Lars Bak (and I have utmost respect), Mike Pall has done a lot more with about 1% of the resources.