After searching through a few iPhone 4 forums have decided this is the one for me.
Spent the last few hours reading almost everything here. Already picked up a couple tips and have had to stick my name down for one of those Vapour cases, they look awesome!
I was lucky enough to get my iPhone 4 from apple so it's sim free. Not all UK carriers released the iPhone 4 at the same time. T-Mobile UK only released the iPhone 4 to their customers on Friday! But yes now as far as I'm aware every UK carrier offers the iPhone 4.