The MusicGremlin could be a hint on what technology Apple is working on for the iPod. There have been rumors for the past couple months that Apple will be releasing wireless versions of the popular iPod device, and soon it could be reality. In the meantime though, MusicGremlin has a 4GB and 8GB model of an MP3 player that will allow a user to download music directly from a pc via a WiFi connection to the hard drive on the MP3 player.
They also have a service for the device that is used to download the music, and even though you have to pay a monthly fee you do get to download unlimited songs to the device. The service is currently in a closed Beta testing stage but I am sure we will see something similar coming from Apple using iTunes. It is just a matter of time.