SD and USB in a head unit would be GREAT features. I'll wait until the big boys (Sony, Pioneer, etc) catch on and provide 2 powered USB ports for portable HDD's that need a little extra juice. I'll also be waiting to see what methods of cataloging/indexing will become available as more and more folks start plugging portable HDD's and large flash media drives into their head units. I know that with 70 GB of music even my desktop has trouble presenting me with THAT many songs in a quick and easy format. At a minimum these things should have the ability to read playlists in several different formats and sort and filter based on title, album, artist, and genre.