Wheres the option for both? Its entirely possible and I am hopeful that you can make conjurer a Whm OR a Blm. Likely the same for Thm atm. Such as Blm/Thm, Blm/Con, Whm/Con, and Whm/Thm.
I took it to mean job classes would replace the spot that is currently physical level, in that one will have a weapon class AND a job class with the ability to mix and match several options. At least I really hope that is the case.