I got in touch with PayPal about their Website Payments Pro feature which lets you process payments through PayPal without sending users to the PayPal site. It also gives you a 'Virtual Terminal' to take credit card orders over the phone, in person, etc.

I asked if the feature would be coming to the UK soon, or was in the works, and PayPal said:

Based on your email, we understand that your query is regarding the availability of Website Payments Pro in the UK. Unfortunately, at this time, this feature is only available to US Business account holders. We do not have any updates yet as to when this feature will be available in the UK. UK customers will be informed as soon as this feature is available to them.

So, don't hold your breath, but PayPal has had a way of launching cool new features by surprise over here, so one day maybe.. :)