Sadly, I suspect Apple do have restrictive limitations regarding the iPhone and the customer paying, because they are a premium brand and want to maintain that. iPods have always an expensive choice for an mp3 player... unfortunately, they're pretty much worth it. The same presumably goes for the iPhone - they don't want companies footing the bill and throwing iPhones around like smarties, because then, instead of "woo, you've got an iPhone!", it'll be "oh. Another iPhone."
Of course, this will happen anyway eventually, but as with the iPod (and iMacs), it'll happen in a way that convinces everyone they've bought a bit of slightly exclusive posh kit, rather than they've been mass marketed too

Still, I suppose I can't complain - it's a wicked handset, and my mp3 player is busted, so I'll make myself feel better by adding up the price of a shiny new phone with the price of a shiny new mp3 player.
