I shoot NEFs and eventually convert to DNG. The DNGs have large JPEG previews embedded in them, and some programs let you use the embedded JPEG files. I find this useful, for example, when I want to upload basic proofs to a web gallery for review.
In PM 4.5, it seems the only way I can use the previews embedded in DNG files is to "Send Photos via Email..."
It would be very useful if the "Save Photos As..." command would permit processing (with the normal resizing, sharpening, and embedding of sRBG profile) only the JPEG preview when it encounters a DNG file.
Thanks,
Kevin