AMD has confirmed that to support AMD Athlon 64 processors revision E motherboards will need a BIOS update. The new CPUs, which contain many enhancements including SSE3 support, should not present any other obstacles, however.
"Mainboards need fresh BIOS revisions to support the new revisions of AMD Athlon processors. The new rev parts are 90nm, with SSE3 support, and a few tweaks to the memory controller and a different OPN." - AMD's spokesman Damon Muzny.