Beta is three parts: Trainer's Guide, GM's Guide, and Bestiary.
All the Moves, Classes, and such have been fluffed out (the Trainer's Guide portion), and I'm compiling all the myriad word docs into one cohesive pdf file on that.
Mystic's still not planned for Beta, though. Just not tested enough yet.
Player's guide isn't too far off from done, though. I'm actually working on it right now (well, was till I got distracted by those character sheets), and I'm pretty much down to writing up rules and making it a more interesting read.
GM's guide... hasn't really been touched yet, at least on my end. That's the one with more "How to run this, here are the rules you don't want your players knowing, etc." By that last bit, I'm referring to things like capture rates - you want them knowing that certain things will benefit the capture, but knowing the specific bonuses encourages metagaming.
Bestiary is the updated Pokedex. Fluff on that seems to be somewhere in the "F-G" range, so that could take a bit. I'm thinking the majority of the actual content for that sucker's ready to go, though.