Rick first of all. thank you for your highly insightful post about how to approach your W. I feel that I am somewhat in the exact same situation as you. I termed it as my W doesn't want out, but she doesn't know if she wants in or how to get there.
As for the dream, I watched a Nova special on dreams awhile back and it went into much detail about the dreaming how if affects our bodies etc.
One theory is that dreams sometimes represent a dry run for worst-case scenarios so when they come up in real life we will be prepared. Under that theory, you W's dream seems to fit that mode. It was scary, but the main issue is how she approaches and reacts the dream and how you show her it was ..."just a dream."
Patience is bitter, but its fruit is sweet. --Jean Jacques Rousseau.
