The supported memory list appears to be quite long. I have old DDR2-800 memory I'm going to try on it, specifically OCZ gold 1GB X2 and OCZ platinum 1GB X 2, the platinum is on the list but the gold is not. You don't know until you try, also some people don't realize that sometimes RAM voltages need to be changed in the BIOS. Also, sometimes you need to install just 1 memory module to be able to boot and get into the BIOS to make changes and then install the other sticks.
If you have been looking at this mobo then you have no doubt compared it to the GIGABYTE GA-MA770-UD3. Version 2 of this board has a SB710 and thus supports ACC. Newegg is shipping the rev2 as are most other retailers even though they have not updated the specs.
The GB mobo has an even smaller supported memory list but it has some flash the ASUS doesn't like 2 extra USB ports, 2 extra fan headers, an 8pin CPU power header (ver2) an extra PS2 port and an extra PCI Express x1 slot. But one less PCI Slot, no parallel port and no serial port.
All in all I think the ASUS is a higher quality board and certainly it has a nicer NB heatsink. On the other hand the GB board is a bigger seller and if you google these 2 boards you will find much more info/reviews on the GB board.
my 2 cents
edit: here is a link to the supported memory list at ASUS, it is a zip file