As far as I know itunes can play anything from 8 bit to 24 and 44k to 96k, depending solely on whether your computer (or Mac) can play these. As I understand it, Itunes is just a way of grouping files together into library or playlists but it isn't "processing" any data as long as you don't tell it to automatically convert formats or anything. In fact, you don't have to import any audio files into Itunes at all for them to be able to play, as long as they are already in "the box." While Ipod may not be able to play anything above uncompressed AIFFs at 16/44, it can of course store the files, and that means you can play them on another device (like another Mac) with capabilities of playing different types of files. I have used Ipod to backup 10 GB of 24/96 audio before and was lucky to have it there when another drive crashed, even though I couldn't play the audio through the Ipod.