As first reported by LiveSide, Microsoft has begun offering the Zune Pass subscription service to customers in the U.K. The Zune devices have never been sold outside North America, so there hasn't been much reason to offer the related subscription service, which offers unlimited streams and temporary downloads plus 10 permanent downloads a month. But the Windows Phone 7 software has the Zune HD's functionality built in, and with that phone platform slated to launch worldwide later this year, it makes sense for Microsoft to begin testing it now.
I was able to confirm the report for myself by signing up for a new Live ID account and visiting the U.K. sign-up page here. Prices are 8.99 pounds per month, or 26.97 pounds for three months; you can also sign up for a free 14-day trial, but you will have to enter a credit card number. It's not clear what signing up today will get you--Microsoft might add Zune Pass music to the Zune for Xbox 360 service in the U.K.--but eventually you should be able to stream music from the Zune library to any connected Microsoft device.