I've had to be a registered and verified member at Asus's support before I could download the BIOS - this entails registering for an account and registering your mobo.
Aside from that, no. I heard 0304 was released for my M2N-E but, now they've pulled it and the 0302 Beta down. Asus's support site is weird. You may try the forum specific to your mobo @ Asus...
EDIT: myocardia is dead-on - don't e-mail them unless you enjoy wasting your time - call them if you need to contact them.