Yes you can force a reload, either through the EOS utility or through the camera firmware menu option. You just need to drop the firmware in the root of the card (I used the SD card) and in the firmware menu it will ask to upgrade.
Personally I am waiting for the official release, but here is the md5sum from the file I pulled from the web
$ gpg --print-md md5 5D300121.FIR
5D300121.FIR: 3C AB 84 0C D3 D4 CF 17 5B 5B 4E 0E A5 14 EB A9
I am going to compare that to what Canon releases next week.
Can anyone with the firmware from canon confirm the checksum? Even if the canon release is different one will still be able to update to the canon release version overwriting this one, correct?
Pstodart: Did you figure out the audio recording? Video/audio to the card works as expected right?