Forget this phone on the upcoming O2 and Vodafone LTE networks, none of the three versions of the phone that are being released for different markets support the LTE frequencies 800 and 2600 that these networks will use along with large parts of Europe.
They could always release a new version later, they have done that in the past
I've had a 3GS, a 4 and my current 4S but I don't think I'll be going to the 5, too many disadvantages for me at the moment.
Roll on the iPhone 5S