This will be the Palm Pre all over again.
O2 put the Pre as a premium phone at a similar price point to the iPhone. (3GS I think). Was anyone surprise that people bought the better known and supported iPhone rather than the Pre?
It does not matter how good the phone is O2 and Apple will heavily promote iPhone, People have Apple apps bought, and while Amazon may have deep pockets, the fact this is an O2 exclusive it will probably see it smoulder on for a while then burn out.