It seems like 3.5" OLED panels are coming. The new Vosonic 8390 will have one, and also there were reports of a prototype RFID project that will sport such a panel.
I wonder who is making those panels? My bet is on Sony. LG and Samsung make AMOLED panels, but only at 2/2.6" size. Sony however said they have begun to make AMOLEDs in the beginning of 2007, and already years ago they made OLED for a Clie model that was over 3" large.
Toshiba has announced a new 21" OLED prototype, and also says they have been making 3.5" OLED panels. I guess they are the source of these new large panels we start to see.