it can be, amitool seems to work. However no idea if properly since i dont have board and about its size, i seriously have no idea why they need that much because quick look at this bios shows ~6.3MB of free space, so this means they could easy fit it in to 2MB.
You can find it here : megaupload.com/?d=VC1MJR7L if the link is broken here (mine) : f*p://82.239.144.183/program/ASUS/ASUS%20-OEM-SLIC/Asus-Bios-Slp-Slic/Slic-2.1/ choose the line N° 2, not verified by me, you have the original Bios in it. Tell forum if it is OK.
Maybe they're planning to bring out an update to efi for you board? I think efi takes up more space than a bios.
@legace and @yen, I tried the slic vers : 1204 of this Mobo (P7H57D-V EVO) with the asus cert and oem ser and successfully be activated. Post here : "h**p://forums.mydigitallife.net/threads/7500-All-Slics-2.1-(Modded-Bios-List)-Note-For-requests-use-Bios-Mod-Requests-section?p=286515" date : july 6th However new version 1304 since july 21th, asking or trying to mod it.