Chalk one up for Ars Technica's Opposable Thumbs crew and their Xbox 360 "insider" as newer versions of the Xbox 360 (non-Elite versions) with HDMI output have already begun appearing in stores. A commenter in a Shacknews thread boasted of his recent 360 acquisition, wondering why his Xbox 360 Premium came equipped with an extra audio/video port.
The console clearly displays a manufacturing date of July 4, 2007, indicating that Xbox 360s that post-date that are likely to be of the new, HDMI ready variety. No official word yet on whether the new box is sporting a CPU of the 65nm manufacturing spec, but we'll get our magnifying glasses and rulers out to check as soon as is humanly possible.
One additional note, it appears the box for the new Xbox 360s makes no mention of the change, nor is an HDMI cable included in the Premium package as it is in the Xbox 360 Elite. Buyer beware.
Xbox 360 Premium With HDMI [Picasa]