Just spotted this bit of info at AMDboard.com:
We are stunned to learn that MSI has produced the first motherboard socket 940 dual Opteron that works with Athlon 64 (socket 754) too! The board is named K8D Master2 FAR and, at time of writing, we're not fully certain if the board will request any kind of adaptor to fit the Athlon 64 into the Opteron socket or if AMD is not going to produce a socket 940 version of the Athlon 64!
We are stunned to learn that MSI has produced the first motherboard socket 940 dual Opteron that works with Athlon 64 (socket 754) too! The board is named K8D Master2 FAR and, at time of writing, we're not fully certain if the board will request any kind of adaptor to fit the Athlon 64 into the Opteron socket or if AMD is not going to produce a socket 940 version of the Athlon 64!