IIRC, in the past when ASUS have released a beta version, there was no "SE" in front of the version number of the BIOS.

I'm not saying that the 1004 isn't a beta, but if naming conventions mean anything, and ASUS is intentionally doing this, then the SE1004 should be an official release. ASUS download web site is so wonkey at times, I doubt that it's been updated to reflect this.