The CAA have now extended the transition period until 30 Jun 2009.
Avionista - there is no need to rush into changing to the new system. Just make sure that your 'rolling validity' period is still valid when you do though! I'm glad that you accepted the safety value of the refresher flying training you had in Oct 2007.
The 20 Nov 2005 CAA Regulatory Review indicated that for 'mainstream' GA, the fatal accident rate was 1.3 per 100000 flying hours, whereas for gliders and microlights, the rate was nearly double at 2.5 per 100000 flying hours. BGA, PFA/LAA and AOPA all accepted the value of refresher flying training - clearly you are one of the wiser folk who also understands that!
Crash one, the new system does not apply to you until you changeover to it! Your SSEA Class Rating is valid in any case until Jul 2008, so I suggest you changeover before then (it shouldn't cost you anything). You then have 24 months from that point onward to do your 60 minutes of flying training. If you buy your own taildragger (enjoy!) and insurance is a problem, you can of course do the flying training in a school tricycle undercarriage aeroplane. So, for example if you changed over on 10 Jun 2008, you would have from then until 9 Jun 2010 to complete your 12h-in-24m of which at least 1h (total) must be with an instructor and 8h as PIC - and you have from 10 Jun 2009 until 9 Jun 2010 to do at least 6h of those 12h.