The iPhone is not unique anymore... there are many similar alternatives on different platforms (Nexus one, BB Storm, Palm Pre). They all have their differences, but overall they are all similar enough to remove the unique label.
I agree with jsntrenkler that the operating model apple uses to control the user experience is unique and this is what makes it more popular (or less popular) with a given customer base.
In general BB = Business users, Android = PC Geeks, iPhone = everyone else.
Not knowing more about your project I dont know if the following applies, but if I was working on your question I would look at the product lifecycle modified for the iPhone concept
Unique at release
Copied by competitors / no longer unique
In need of a product differentiation strategy
Release new concept
IMHO the iPhone is still very unique. There are many touch screen phones out there but none of them deliver the user experience that the iPhone does. Come this summer the iPhone will be even more unique as OS 4.0 is going to show the world a new way and in my opinion better way to handle muti-tasking. If it had not been for the iPhone the BB storm, Nexus One and all the other touch screen phone would not exist. It took Apple to show the world how a smartphone should work and what was possible on a mobile platform.
The iphone was very unique in 2007 but in 2010 the uniqueness isn?t as great anymore. Sure there were touch screen phones in the market before the iphone but the iphone kinda set a standard for an all touch screen phones. One thing the iphone is unique in is the user experience. I think the ease of moving around on the device is incredible. Like I said before; now that it is 2010 a lot of companies have caught up to Apple and some are providing some uniqueness of their own. The iphone to me is still the best phone but as far as being the hottest phone I think it?s surviving now a days solely on it?s name and popularity. I?m sure come this summer Apple will create something amazing again.
The reason cloning people would not work is because no body respects a copy and not a perfect copy at that, the original person would always be better, well the iPhone is better then it's clones as a whole