I see the update text above the link to the SN dated 1st May 2012 as highlighted by LXGB but has this important update been disseminated via any other means such as a re-issue of the SN or publication of an IN because I can't find anything.
New SN now issued...
SN-2012/010: Delay to the Introduction of Visual Flight Rules (VFR) at Night in the UK
2 Revised Date of Introduction of VFR at Night
2.1 In order to allow the changes to be considered in full and to allow stakeholders sufficient time to implement the changes the CAA has elected to delay the implementation of this change to after the completion of the Olympic and Paralympic Games.
2.2 VFR at night will now be introduced on 17 September 2012 coincident with the introduction of Part-FCL in the UK. Until this date aircraft are required to comply with the Instrument Flight Rules when flying at night in accordance with Rule 20 of the Rules of the Air Regulations 2007.
2.3 A further Safety Notice will be published shortly which will give full details of the conditions and implementation arrangements.