Here's a example of releasing the same motherboard all over again:
http://www.techpowerup.com/tags.php?tag=AMD+790FX
First 790FX came with SB600 southbridge and was a AM2+ board, next they upped the southbridge to SB700 and then made it to a AM3 board with SB750. At least they should all support AM3 processors.
Last step is of course with DDR3, so that's ok, but talk about a "new" board when the chipset came in 2007
