Sony usually releases new devices in October. In the past these have been US-only. It is certainly possible that they will release early, and simultaneously in more countries, this year.
A brand new option is the COOL-ER Reader
. It has not been released yet, and early indications are that this won't be a very exciting device. It does support Adobe ePub though, which is important for new releases in the UK. This is the only UK-based EInk device so far as I know.
I like the BeBook line, which will soon include a 5" device (BeBook Mini) and a high-end device (BeBook2). Currently the original BeBook supports MOBI DRM (encryption), but there will soon be firmware that instead supports Adobe ePub DRM and the high end device may be ePub-only. BeBook says they will be in UK retail stores soon.