There are some reports from Japan that the new Sony PSP2 mobile gaming console will have an OLED display. The report says that the display will be 'larger than normal' - the original PSP has a 3.8" (480x272) LCD, so we assume that the OLED will be 4" or more.
Sony are expected to announce the new PSP later this week. Other unofficial features include 3G support (for over-the-air multiplayer gaming and game downloads) and Wi-Fi. This is not the Playstation Phone that is also expected from Sony, and the PSP2 will not include phone capabilities.