In case anyone's wondering about file formats, Amazon states the following: "Supports MP2, MP3, WAV, WMA, APE, FLAC, AAC, AIFF, OGG and other music formats Supports up to 192K / 24BIT sampling rate, while supporting CUE index playback, seamless playback".
What I don't understand is why with all this processing power, there doesn't appear to be a recording function.
[edit: As per Anthony's comment below, additional sites state that ALAC and...