If you follow a lot of UK government open data people your Twitter stream may have lit up with tweets this morning (rather early in the morning, for those of us in North America).
There was a hashtagless event that combined a launch of the Open Data White Paper and Departmental Open Data Strategies
with a relaunch of data.gov.uk itself.
UPDATE 2012-06-29: The OKFN blog has details on the site and the CKAN code that powers it - UK Government Releases Open Data White Paper and new Data.Gov.UK ENDUPDATE
I Storified what showed up in my Twitter stream (I can't guarantee it's full coverage, it's just what I saw from those I follow).