Slopey, virtually all of your post is totally incorrect:
As from 1st July, you will only be able to add an IMC rating to a CAA licence - you won't be able to add it onto an EASA licence (which a JAA PPL will become), and you won't be able to use it on EASA aircraft.
The CAA will have no physical method of being able to print JAR-FCL licences after 30 Jun, so the IMCR will have to be included in a supplementary UK licence
unless the CAA has found a simpler solution by then. However, you
will be able to use it on EASA aircraft until at least Apr 2014.
So - if you want to fly anything but permit aircraft and exercise the privileges of the IMC rating, you need to get it on your JAA/EASA licence before the 30th of June. If you want to fly a permit aircraft on a CAA UK licence with an IMC, you can add that to your licence post 30th June.
Wrong! The situation regarding PtoF aircraft is a separate issue and has nothing to do with EASA. LAA has made certain proposals for flying PtoF aircraft in IMC, but this is very much Work in Progress.
The IMC itself will be valid until 2014 - after that, it will cease to exist. As far as EASA licences are concerned, there is talk of grandfathering/converting the rating to some form of UK only restricted IR.
The IMCR will NOT 'cease to exist' after 2014. However, how it may be used on EASA aeroplanes after that date is under debate.