it means it supports DDR2-667 and DDR2-800. simple as that.
what the CPU's FSB/HTT is is another matter, and not dependant on the motherboard (unless the CPU's FSB/HTT is more than the motherboard supports) . AM2 CPU's will be DDR2-800 standard as far as I know.
if the CPU only supports DDR2-667 and you want to run your RAM at DDR2-800, then you will need a divider, or you'll need to overclock the CPU.
if the motherboard doesn't have a divider, then you're either stuck with 667, or you overclock. even if the RAM is designed for DDR2-800.