In regards to purity, what must be preserved is the interface. Fortunately, music, photos, and yes video* are suited to the scrollwheel/buttons on the iPod. There are some that fervently wanted the iPod to become a phone. Think about that. Unless Steve is a big fan of the rotary dial, to preserve the iPod's UI, a phone is not going to happen (thankfully).
*Mmmm, shuttlejog.
Screed