The UK has been working on this for a while. There is a joint CAA/Industry working group which has worked to ensure as seamless as possible a chnage to this invention of EASA by 2015.
We have been asked to provide information to EASA at the next FCL_PG meeting.
All 'grandfathering' has been drafted, as have all other aspects of the Aerobatic Rating, including instructional requirements. The AOPA Basic Aerobatic Syllabus will be aligned with the requirements of the EASA Aerobatic Rating; in fact the CAA has had the AOPA draft since January 2012 and we're still waiting for a response.....
We also have a key objective - the deletion of the ridiculous '40 hrs PIC since licence issue' before anyone may be granted the Aerobatic Rating, after completing the course. You could have 100 hrs of dual aerobatic training, but unless you've logged 40 hrs of aimless 'hamburger run' PIC time, you will be unable to apply for the Aerobatic Rating. For which you can thank ze Tchermans.....