Engadget just posted a review of Cowon's S9 Curve player. They love the AMOLED display -
"The 480 x 272 resolution screen is positively gorgeous to look at, displaying rich, vivid colors on everything lucky enough to tickle its pixels. Video looked superb, images were almost unbelievably sharp and bright, and the overall user interface was quite a joy to gaze at.
Other PMP makers should definitely give AMOLED a look"