It looks like the Tizen image flashing instructions are out! I wouldn’t have found out about it had not my good pal jezra posted a link in the forum (I’ve been waiting for it to be announced in the mailing list which was promised 2 weeks ago).

Anyway, below is a summary of the steps, and oh, you need to be running Ubuntu (32-bit):

• Download the Tizen image
• Download and install the lthor library
• Turn off device
• Enter download mode by pressing <volume-down> + <power> buttons simultaneously
• Connect device to the Linux PC via USB
• Upload the image with:
  

  sudo ./lthor lb-tizen-1.0_20120613.10-rs.tar.gz

• Wait until upload is finished and the device does a reboot

The full, detailed instructions are at the Tizen.org Wiki.

Thanks jezra!