Im pretty sure based on what I read that this is the first of what is basically a sequence of commercials.
This first one is meant as an introduction for the japanese consumer, parallelling the introduction Hikaru Utada is having to the DS.
In subsequent commercials, more and more of the DS and its features will be introduced and spotlighted. Very likely, as the end of that commercial hinted, the touch screen will be the star of the next commercial.
I think its very clever....as opposed to having one commercial which is like ITCANDOTHISTHISANDTHISANDOHYEAHTHIS you have a gradual education of sorts.
Oh, and shes really cute. That is also very good.
Nintendo -> Not afraid to use the power of a little cleavage for the betterment of all mankind.