From what I heard both the Panasonic plasma and Sony LED models will be released at around 4 large for the 50+- inch.
Sony's current XBR line doesn't fetch more than around $2,500 and Panasonic is around the same.
Samsung I heard was doing both LED and Plasma for for under $2,500 for the 50 sizes which is a little more reasonable imo.
EDIT: Correction - $2,500 for the LED 40inch model.... 4G for the 55inch from Samsung
Oh ya and apparently you need a Samsung 3D ready Blu-Ray player which retails for $400...