I like the commercials. Of all the things that WM offers, I think the ability to carry your stuff with you is one that translates well to all levels of tech expertise. Using the term "windows stuff" helps stick the idea that what's on your computer at home can be on your handset along with you without getting too specific and losing some potential buyers.
Apple was tremendously successful with "there's an app for that" even though we knew that there was an app for that on our phones too
It just needs to translate into "this phone could work for me" in the heads of the viewers.
I realize that the vast majority of phone users have no loyalty and probably no actual knowledge of what OS their phone uses. They just want it to work for them.