that's BS. Asus for example decided to do their whole M4 line, and leave behind their entire M3 line customers. For example, the M3A78-EM and the M4A78-EM have the exact same chipsets, yet Asus only created a BIOS upgrade for the M4A78 and their official response is that that is where they draw the line, and they have no plans to release future updates for the M3A78. As a result they have lost my business and respect forever. My M3A78-EM is less than a year old. So much for being future-proof Asus, hasta la vista.
*** that's the same Mobo I have...
I still have hope that they will later do the bios update... for example, the M2N-E did not support anything past Phenom 9950 125W for a long time...
Now they finally made it support AM3 CPU's
But as you said, it would not make sense as the M3A78-EM and the M4A78-EM are pretty much the same.
Good motherboards overall, all solid caps unlike some of the more expensive M4A785's