Offering a heads-up that there's a way to embed covers in *.OGG as Base64 encoded text so they can be placed in a Vorbis comment. Windows freeware program Audioshell can do this, as can Softpointer's other program Tag&Rename and JRiver Media Center.
It would be nice if playing software coders got in touch with nabobs at Hydrogenaudio to implement standards-compliant support.