There is a direct relationship between resolution and size of a Plasma TV panel. The challenge is actually to develop a small panel with a high resolution.

Panasonic introduced now a 50 inch Plasma HDTV with full 1920x1080 pixel resolution (1080p) called TH-50PX500.

Update 11/03/05:
TH-50PX500 is actually not the product id for the 1080p 50 inch Plasma TV. Apparently Panasonic did not even assign a model name yet. The TH-50PX500 is on the market and is a 1366x768.

Panasonic just recently introduced the 65 inch model TH-65PX500 in this 1080p Plasma TV series. The Panasonic TH-50PX500 has a 3000:1 contrast ration.

The Panasonic press-release claims that it is the world's smallest 1080p Plasma TV as of October 3rd. Pioneer claims also to have developed a 50 inch 1080p Plasma HDTV reports Nikkei.Net (Subscription).
There is no information on when the new 50 inch Panasonic HDTV will hit stores. The Pioneer 50 inch 1080p Plasma apparently is slated for May 2006.
More details in this Panasonic press-release (Japanese).

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