I just saw on the internet that Orange UK will be supplying the iPhone 3G and 3GS. My SIM contract is with Orange UK and my current iPhone 3GS in from O2 UK and is Jailbroken.

Does anyone know if the official Radio ROM from the Orange 3GS will be available for us to use in O2 iPhones when Orange release it?

The ROMS are not different.

Apart from a small Operator configuration file (.icc) which can be OTA'd to your phone over the network or through iTunes, there's no significant difference between a Vodafone Italy iPhone and a UK O2 iPhone.

so when in the UK the iphone is available on Orange (and maybe later on vodafone or others) does that mean we will be able to get it to work without a sim-unlock? Or is there likely to be another way that they are tied to the original provider?