He said it will be 1080p, supporting 1080i and 1080p.
How they manage it can be debated, but I think it would be prudent to wait and actually see something of the (near) final product before proclaiming what they will do.
"Supporting" 1080p & "Rendering" at 1080p are different cases.
Supporting basically means the old HDTVs will be able to display the game in HD.
Many old HDTVs only supports 1080i & SD resolutions...a 720p game wont get displayed & so the people are forced to play it on SD, to avoid this they upscale the 720p image to 1080p & once its done the HDTV can display it...Thats supporting 1080p for you !