When I discussed my situation, first withregular Samsung Customer Support 800-726-7864, I emphasized that I expectedto pay for a repair of my TV, but it wasn't reasonable for Samsung to not stocka replacement board anywhere in the world. Nor, was it reasonable that Samsungdid not plan another manufacturing "run" for the board. BTW: youcould not then find a used part on eBay. That made the relatively new TVuseless. Samsung agreed and assigned me a new ticket that authorized anexchange. Then I started dealing with the Samsung Exchange Department at 201-727-5622.
In your case, obviously it's not Samsung's faultthat the screen cracked (and I know you're not claiming that). If Samsungcan't furnish a replacement screen because the company discontinued its plasmaline, it should offer you some consideration.
The questions become what will they offer, whatwould you need to pay.