There are rumors that Microsoft is planning a new Zune player - Zune HD. They say it will feature an OLED display. No info on size, but it will have 16:9 aspect ratio.

Zune HD leaked photoThe Zune HD?

Other specs include 16/32GB of memory, HDMI slot (thus the HD part of the name). It will also support 3D Xbox games, whatever that means.

Kyulux - Hyperfluoresence OLED emittersKyulux - Hyperfluoresence OLED emitters