I'm not sure we can read anything into that.. they may simply be doing that to prevent others from taking it and causing market confusion...
Considering that they consider that Office 365 can be considered a success, I would not be surprised if Windows could be offered like that too. It might even be acceptable to some.
I'm pretty sure that, if anything, this becomes the new name for the Work&Play Bundle. I don't believe Microsoft can survive the fallout from customers discovering they need to cough up the big ones one year after they buy their computer.
Perhaps the core OS will be free. If you want Aero or some different function like advanced gaming this could be chargeable.