Customizable infos below the Preview
I think it would be valuable to see, instead or beside the file name ("PHOTO 001.JPG"), the IPTC Caption/XMP Description as it were a caption to a painting above. I used Google Picasa in the past and loved to see the caption just below the image large view, where it was also editable.
More generally, I'd suggest that the area below the Preview (see attached screenshot) should be customizable exactly as the area below the Thumbinails in Content panel (by means of Preferences > Thumbinails). This way, every user will display which info he/she likes most, instead of having to seek for them below the thumbs or in the Metadata panel.
For example one could set:
Caption - 1/100 s f/4.5 ISO 200