The two things are inseparable at this point. So I don't really understand the distinction you're making, it isn't as if people buying a Lumia don't know it will be running Windows Mobile.
No, I would bet most people buy them because it's a Nokia, regardless of the OS. Case in point, my mother who seems to only buy Nokias because they used to be the best brand. I told her to buy an Android phone and she somehow found and bought a Nokia Android phone (I didn't even know they existed). It had some weird Metro skin too so that it looks like a Windows Phone but is actually an Android.
> "I told her to buy an Android phone and she somehow found and bought a Nokia Android phone (I didn't even know they existed). It had some weird Metro skin too so that it looks like a Windows Phone but is actually an Android."
I think you're referring to one of the Nokia X devices: