Upgraded HDMI-enabled 360s have been appearing on US store shelves this week.

The High Definition Multimedia Interface Connection, which supplies users with the highest possible quality visual connection to compatible televisions, has previously only been available on the Xbox 360 Elite machines, for which it has been a key unique selling point. With Microsoft now supplying the connection on premium models the gap between the Elite and Premium has narrowed.

"We are offering an HDMI port for Xbox 360 simply as another choice in Xbox 360 owners' games and entertainment experience," said a Microsoft representative. "Retailers are gradually introducing HDMI-enabled Xbox 360s into the channel to meet demand. We have not announced any plans to add the HDMI to the Xbox 360 Core system," they added.

External packaging of the US Premium units carries the HDMI logo to make it easy to identify units which are HDMI enabled.

Microsoft UK is yet to confirm whether European gamers can expect a similar upgrade to the Premium units but it seems likely that this new standard will soon apply here as well although there has been no indication of when this might be, nor when we can expect an announcement.