I have the same thing going on with my Mitsubishi TV.
All the HD DVD & blu-ray movies come in as 1080i and when you push the "Display" button, it also says "1080i". But the TV deinterlace to 1080p just like everyone says.
Now if you were like Greg with his new shiny 73" Diamond Mitsubishi DLP, you actually get the 1080p right off the bat.