Hi gang,
I have a solution for this! After I created this post, I created a ticket with support and they resolved it for me.
Here's the skinny: El Capitan changed something permissions-wise with access to files/data on the Bootcamp partition. VMWare indicated they were working on fixing this, but in the meantime what they had me do got me back up and running... just remove the Boot Camp VM entry in Fusion and recreate it. I'd recommend backing up beforehand just in case, but this process does not touch the data on your partition, only Fusion's definition of the VM and how it accesses your partition.