This is an interesting point. Both PS3 versions, the $499 20GB version and the $599 60GB version will include the new Blu-Ray DVD drive, which many buyers will be looking at as a cheap way to get one of the first Blu-Ray players for their home, without paying a hefty $1000 price tag for a standalone player (similar to the PS2 approach when it first shipped with a DVD player).
However, only the $599 version will include an HDMI output, which is what the industry has agreed on as the standard output to a HD display to display the content in the highest resolution possible. The new add-on HD-DVD drive for the XBox360 also has the same issue – no HDMI output.
This is important, as this article on the Register notes, because without the HDMI output there is no HDCP copy protection, and therefore the output from the hidef disks will default to a lower resolution output. Something to be aware of…