I think this has been an interesting question, it is apparent that the vast majority of people either have never owned a video capable phone, or never made video calls. But there does seem to be a (probably fairly small) market for people to communicate with family whom they live away from.
Whilst some people do point out that if anyone can make it popular it is Apple, I still have trouble imagining people walking down the street looking into their phones.
- I don't particularly want to be looking at the person i'm talking to on the phone.
I do however use Skype with video quite often, but that is normally with family members in other states or countries and it is different to be seated at a desk doing a video call than with a mobile / cell phone.
I'd be interested to hear others opinions.