If I had to guess, the WP7 ads deliberately minimize the product itself. The subtext here is that WP7 is not a robot that controls your life or a walled garden from which you cannot escape. Instead, it is a seamless extension of you.

I like the adverts. We'll have to see whether Microsoft takes the spirit of their advertising into their software.

Which is to say, everyone already knows about Nikes, Kellogs, and Wonderbra - raising the brand awareness to a level that transcends the commodity nature of the product (not just "a pair of runners") is the task at hand.

It may not be the best marketing position for a product playing catchup, where public awareness is very poor, and the whole "mobile OS" product is not at all commoditized at this point (though Android is trying, I suppose).