I tried out flashrom on an ASUS A8N-VM CSM board: read seemed to go fine, but write failed. Information about the board: http://www.asus.com/product.aspx?P_ID=JBqqlpj4cspbSa3s
flashrom -V, lspci -nnvvxxx, superiotool -deV, flashrom -rV and flashrom -wV output is attached. The BIOS I was trying to write was the rev 1001 one available from the above ASUS page.
Per agaran's and roysjosh's friendly help on IRC I checked the BIOS I read with -r with -v and it says VERIFIED so I suppose I'll go ahead and reboot later today.
One note about the board testing Wiki page you may want to clarify:
"To check if you can read the existing BIOS image from the chip, run flashrom -r backup.bin. Make sure that backup.bin contains a useful BIOS image. (Some chipsets will return 0xff for large areas of flash without any error messages.)"
For a BIOS newbie like me, the remark in parenthesis doesn't tell much - is it a good or a bad sign if a chipset returns 0xff for large areas of flash without any error messages? (Bad, I guess ;))