Ok, thanks for all your answers. I understand that there will be a transition period. But if I am not mistaken after reading through the above sources of information, from April 2012 onwards only new EASA licences will be issued.
So how would this affect for example instructor ratings, e.g. SFI, TRI, IRI, FI etc? Requirements for initial issue, revalidation, renewal etc. will probably change, but when will this all become effective? After or before the transition period? Anyone has got a clue?