Homeguard - The NPPL/LPL is not relevant to this discussion, which refers to UK national licences such as the lifetime PPL and the UK National (not JAA) CPL and ATPL that a number of pilots (me included) still hold. There is a distinction between a UK-issued JAA licence and a UK National licence that you seem to have missed.
It is not correct to state that all licences are now EASA - whilst it is true that the JAA no longer exists, it is also the case that EASA has not yet assumed responsibility for licensing. Consequently, individual member states are having to make their own arrangements to regulate (or not) during the interregnum. This has been complicated by the fact that EASA have been instructed by the EC to abandon the draft implementing rules presented in NPA 17 and 22 and to start again. In any case, the fact that the JAA no longer exists is not relevant as licences are still issued and maintained in accordance with JAR-FCL 1 or 2.
EASA have stated that licences issued in accordance with JAR-FCL requirements and associated procedures are considered as having been issued in accordance with the implementing rules whereas the same cannot be said of national licences. It is only the former that will be able to be converted to the equivalent EASA licence.
flybymike - By the same token, I am acquainted with a number of people who have felt under such pressure. I attended an FTO/TRTO seminar at Gatwick in 2007 at which the situation was explained and a 'strong' recommendation was made that, consequently, all national licences should be converted to the JAA equivalent before EASA took over. I am aware that a number of propective examiners have been refused authorisation on the sole basis that they hold UK national licences. In my own case, despite already holding CRE(A) and TRE(A) authorisations, I have been refused an FE(PPL) authorisation on the grounds that I hold a UK national ATPL(A) and not the JAA equivalent.
shortstripper - Quite correct, provided that you hold a JAA licence at the time that responsibility is handed over to EASA, you can exchange it for the EASA equivalent.