Personally I think you should wait. I'm in the UK and I've wanted one since it was announced in January, however I've opted out of buying into an 18 month contract until they resolve issues with the "phone" part of the device. There are lots of things I can do on my k810i that just blows the iphone out of the water with regards to its "phone" capabilities, which in my opinion should be the most important aspect of it.
And let's not forget the iPhone is also now nearly a year old. And before anyone says, it was released in July, the current hardware for the device was announced in January. They were simply working on the software end for the 6 months after. I'm pretty sure Macworld will see a brief chat on the iphone (hopefully they'll spend the majority talking about MACS), and announcement of iPhone V2. All the carriers have been put in place, so whenever it's ready it'll be a worldwide rollout with a view for Jobs hitting his 10mill target.