Some people don't seem to realize that the United States isn't the onliest country in the world.
Let's say Europe: you can compare a country over there, with a state in the USA.
The big difference is that there are multiple carriers per country (or 'State'). You guys have Verizon, AT&T and some others: for the whole country. I'm pretty sure Europe is able to handle such traffic. Same for, let's say, China. They are already prepared on very much traffic.
And than another thing: you may must pay extra for 'iChat'. AT&T might say "Okay, you can use iChat but than you must pay an extra $10". And next to that, still a lot of phones do NOT support video calls: you won't be able to use iChat, if the other mobile phone isn't able to support video calls.
So...
- A lot of countries can handle the amount of traffic, sad for you guys AT&T apparently doesn't.
- Some carriers might ask money for it, if that happens less people will use it.|
- Some phones will not support video calls, and if that's the case than you can't use it either.
My answer to the topic's starter question: it's possible, but probably not. Sure, maybe Apple wants to give AT&T more time. Sure, maybe Apple chooses another carrier (or it goes for multiple carriers) and wants to see how it works out and how other carriers handle it. They might also wait until more phones are going to support it. I just think they wait until 2011 - when LTE is going to be used, not just in the USA.
And as someone else said, maybe there will be a front camera but without video chatting (which they can easily add via a firmware update later on). It would be smart of Apple to do this, but we know Apple and they probably won't add video conference.
With the 5G they will do something like: "NEW! Video calls on the iPhone, only and alone on the iPhone 5G". Just like with the 3Gs with creating videos, they can add it in the 2G and 3G but they just don't (even though they slowly allow 3th party apps to create video).