Panasonic unveiled the world's largest Plasma TV at the CES 2008 yet again. Panasonic managed to increase the size to 150 inch.

In 2006 Panasonic showed the world's largest Plasma HDTV which was only 103 inches. At the CES 2007 Panasonic displayed 8 103 inch Plasma HDTVs at the booth.

The new 150 inch Panasonic TV has a resolution of 4,096x2,160px. Panasonic says the 150 inch Plasma is well suited for cinema and commercial installations. Update: See also this video of the revealing of the 150 inch Plasma.

I have a 50 inch Plasma in my living room. The 150 inch Panasonic Plasma HDTV has the size of 9 such TVs.
Via the Panasonic CES site.