I think you are all missing the point. I don't have an iphone yet, but I've had several ipods, and I've always been annoyed at how easy they are to scratch. That is something Apple should have resolved, and is not something the customer should have to pay for.
I understand the point of negligence on the point of the user, but the point I am making is that there is also negligence on the part of the manufacturer for not making a more durable screen - especially on a phone, which is something that people are expected to carry around a lot more than an ipod.
It makes great business for all the companies that make protection products, but should you really have to have some sort of protection over your new phone, just to use it? Especially since it's not exactly small already...