With all due respect Jamie....
Unless he gets sole custody...(but even then it would be a battle because the kids are already JW-indoctrinated)
He could lose them forever to even stricter JW thinking since their mother will feel even more compelled to 'protect' them from him/world via indoctrination.
His lil 5 year old's comments show she is already quite able to 'make a stand for Jehovah' and that sort of dedication at that age (minus coaching as his wife denies) is a very strong indication that she would resist him and probably blame him.
I was a little uberite-JWchild similar (but probably more hardcore) to what he describes of his 5 year old's comments.
He can win his child's trust back far faster and easier than his wife and begin to gently teach her the critical thinking skills.
Best to let the fire die to embers instead of intensifying them when it can be avoided.......if not he will only end up in divorce court and the kids will become pawns for the rest of their childhood (if not the rest his life).
Again the WTS is betting heavy on his giving up, becoming indignant or self-destructing.
Please see this thread: http://www.jehovahs-witness.net/jw/friends/230187/2/and-a-new-wrinkle