Dark Star said:^^No . AM3 boards can support DDR2 as well. They can come with only DDr3 or DDr2 or both. But you can use one at a time either DDR3 or DDr2 ..
This is because of dual memory controller on processor . Though DDR2 boards are rare in AM3 case but you can expect some real cheap boards soon.
That's what I meant. Currently board available here, AM2+ support ddr2 and AM3 support ddr3. In future we might see am3 boards supporting both ddr2 and ddr3.