We can't really tell the difference between the FY500 and the FY550, but both they and the FY600 come in flavors
ranging from 128MB to 1GB, play back MP3, DRMed WMA, ASF (what, no OGG?), have a 4 line LCD, an FM tuner, and USB 2.0.
Pretty much standard fare for a smallish flash player, but decent for the lower end.
What we're really looking forward to is the Backphone, however, which looks to be one of the first decent-looking headphones with an integrated-MP3 player. They will play back MP3, DRMed WMA, ASF, and come in 128 and 256MB varities with USB 1.1. What were you expecting?