Sony was the first company to offer a commercially available OLED TV with the XEL-1 back in October 2007. The Sony XEL-1 only has a screen-size of 11 inches and is more or less just an expensive executive desk decoration ($2,499 on Amazon).

OLED-Info picked up a short mentioning of Sony and Samsung unveiling larger OLED TVs at the IFA 2009 in September in Berlin in an article on The Korea Times. Sony is possibly unveiling a 21 or 27 inch XEL-2 OLED TV.
A 27 inch OLED TV starts to get interesting, but more importantly will be at what price Sony or Samsung will be able to offer large screen OLED TVs.

By the way The Korea Times report paints a bleak picture on what electronics companies will unveil at the IFA 2009 - Damn You! Bad Economy.