I'm not aware of any move to introduce a conversion route from any 3rd country licence to the LAPL , particularly as the LAPL is sub-ICAO. You could always convert your FAA PPL to an EASA PPL and then drop back to an LAPL, although I can't see why you would want to.
The European Commission yesterday agreed to extend the derogation for the validation of licences for non-commercial purposes to 8 April 2015 and so, in the UK at least, you can continue to use your FAA PPL in UK registered aircraft.