d747;
The recommendations of BEA's Flight Data Recovery Working Group included that ULB battery life be extended to 60 days, and that the acoustic frequency be reduced to around 9kHz (from 37.5kHz) - to allow for greater likelihood of the signal propagating across deep water inversions.
These measures have already been tabled with the ICAO, but like anything requiring international agreement, it to will take time to implement them.