The anti-spoofing mechanisms first outlined in BCP38 have seen low adoption rates for two main reasons: (1) lack of a business case and (2) the fact that proposed mechanisms become more fragile and less effective the more you move away from the source of the forged packet.
It seems that the IETF Working Group on Source Address Validation Improvements (SAVI) may address both of the problems: it is based on a clearer business case and it provides IP source address validation at the maximally fine granularity of individual IP addresses and as close to the source as possible. SAVI's objective is to prevent hosts attached to the same link from spoofing each other's IP addresses.