Sony make some official announcement about their first OLED Walkman the NWZ-X1000 Series. This OLED walkman features a Display 3-inch, AMOLED colour display, WQVGA(432 x 240 Pixels), 262,144 colours and will be available on 24. April 2009 in Japan.
The NW-X1050 has 16GBs of memory and the X1060 has double that. Sony estimates the 16GB of the X1050 is enough space to store about 4,100 songs encoded at the standard 128Kbps mode. Alternatively it will accommodate 36 hours of 784Kbps video.
Sony OLED Walkman review

Source Sony Impress

Sony show also some Japanese Video about the NWZ-X1000 Walkman: