Is there any way to determine the true resolution of an embedded bitmap image? The Link, Attributes, or Info palette give me no information about it.
I want to export that layer as a PSD at its native size and resolution (so I get maximum image size without interpolating).
What you want is the actual pixel dimensions of the image, which will remain the same regardless of how it's scaled in Illustrator. Go to the Document Info panel > Embedded Images.