Opus motherboards? According to an image put forth by one Electric Tuner, that's exactly what we have. If you'll recall, we heard back in February that Microsoft may be utilizing the Opus mobos in order to fit the newer 65 / 90-nanometer CPU / GPU combo into RRoDed Xbox 360s that are just collecting dust in warehouses. Thus, you'll find no dedicated HDMI port here, but it should operate much cooler and in a more reliable fashion than the pre-Falcon rigs. There's no word on how exactly this unit was acquired (a replacement, perhaps?), but you can head on down to the read link for one more picture and a little discussion.
[Via Xbox-Scene, thanks Leonardo]