Joe, with regards the UK, did you read the AIC linked to above?
2 Definitions of Mode S Airspace
2.1 In accordance with the Mode S EHS RIA, Mode S Airspace in the UK is initially defined as Controlled Airspace around major UK airports and along the major UK air routes (ie TMA, CTA, CTR and en route airspace). Within this the CAA will introduce Mode S Notified Airspace incrementally from31 March 2005.
2.2 Mode S Notified Airspace, in the UK, is initially defined as the extant vertical and lateral bounds of the London TMA. Additional Mode S Notified Airspace will be promulgated through the UK Aeronautical Information Publication (AIP). This is likely to include the Manchester and Scottish TMAs, together with some major CTAs, airways and air routes and is likely to occur before the end of the transition period, dependent on system implementation.