Orange announced today the details of their Apple iPhone launch in the UK.
The Phone 3G and 3GS will be available in Orange stores on Tuesday November 10th starting at 7am, with Pay Monthly and Pay As You Go price plans for both business and consumer customers.

This will bring the exclusivity of O2 for the iPhone to an end in the UK.
Orange iPhone pricing details:

Pay Monthly - iPhone 8GB, 16GB and 32GB models will be available on multiple monthly plans, with the 16GB 3GS free on £45 plans and the 3G model free from £30 plans (both with a 24-month contract). For those looking for full all-inclusive packages, a new high end “traveller” offer with inclusive roaming call and data allowance is available at £125 month. All plans include unlimited anytime, anywhere UK mobile data usage on Orange’s data network, which has the largest 3G population coverage in the UK. In addition customers will also get free unlimited use of the UK's largest single public Wi-Fi network, BT Openzone.

Pay as You Go (PAYG) – Customers topping-up by £50 at purchase will be able to buy an iPhone 3G on Orange PAYG for £333. Any customer buying an iPhone on Orange PAYG will automatically get 250MB of data each month, plus unlimited use of the UK’s largest single public Wi-Fi network, BT Openzone, for 12 months.

Via the Orange iPhone page.