That same site also says Phenom II AM2+ is compatible with AM3, if the rough Google translation is to be believed.

http://translate.google.com/translat...istory_state0=

page 2:
Quote Originally Posted by DinoXPC
Some changes have also affected the storage controller now compatible with DDR3 modules: in this case, however, we must await the arrival of the first Socket AM3 motherboards.
and on the last page with conclusions...
Quote Originally Posted by DinoXPC
Moreover, anyone who wants to buy today a CPU Phenom II and in the near future to upgrade your motherboard with a Socket AM3 with support for DDR3 memory can do so without having to change the processor.
So perhaps some confirmation of what the XS AMD board has been speculated for some time on?