The third generation TPM-3 has finally made it's entry into service after software and engine problems delayed a planned entry into service in the early Summer. The first production facility has now moved over to the TPM-3 and missile loads have gone out to a number of ships. Unlike the TPM-1 to TPM-2 change TPM-3 is compatible with TPM-2 launchers though is 80% smaller. Future purpose designed storage facilities and VLS batteries will thus potentially have larger potential capacities. However the DDS have said that TPM-2 will remain in service until about 2120 at least due to the huge stockpile.
TPM-3 as well as being smaller has a triple warhead option, improved stealth and signal management including a low-emission ion engine. Production will switch fully over to TPM-3 by the end of 2116.
Also announced is the next generation TPM-4 (though this was mentioned in the AABS announcement yesterday). Not much is yet known about the fourth generation missile except that it will have a simplified and optimised design and structure to help with rapid "just in time" manufacture.
