The WSJ has an article about Amazon entering the music player market, potentially as early as this summer:

Now Amazon, the world's No. 1 online retailer, is in advanced talks with the four global music companies about a digital-music service with a range of features designed to set it apart. Among them: Amazon-branded portable music players, designed and built for the retailer, and a subscription service that would deeply discount and preload those devices with songs, not unlike mobile phones that are included with subscription plans as part of the deal.

Seems like Amazon wants to use the physical products market segment as a loss leader which can extend their reach for advertising and brokering information access. Recently they also quietly announced a new contextual ad service.