Panasonic unveiled new 65" 4K OLED TV prototypes at the IFA 2014 trade show. These are just concept models (panels in a stand), and the company's director of home entertainment business says Panasonic is waiting for IFA attendees feedback before they decide to release those commercially.
It is rather surprising to see Panasonic show these TVs. Sony and Panasonic halted their OLED TV joint development project in December 2013, and later on Panasonic (with Sony and the INCJ) formed a new company, JOLED, to develop small/medium OLED panels. Panasonic's OLED TV program development was probably halted, or slowed-down at best.
It's highly likely that the OLED panels on display here were actually made by LG Display (the only company that can actually produce 65" 4K panels at the moment).
LG Display was actually already in talks with Japanese companies regarding an OLED TV panel supply deal back in January 2013, and recent reports from April 2014 said that Panasonic may enter the OLED TV market with LG panels. LG Display is already supplying OLED panels to several Chinese makers.