I bought the WD-52631 about 20 days ago from Circuit City. They wanted me to buy the 2 year extended warranty for $250ish or the 4 year for $450ish. Way too expensive for my liking since i know they make all their money off accessories and ext warranties on your TV. The ext. warranty is inclusive of the manufacturer's warranty, so a 2-year warranty only adds 1 extra year. You may also be using a credit card that extends the warranty. For myself, my credit card doubles the manufacturer's warranty(up to 1 extra year), so in effect, I'm covered for the first 2 years.
so.... purchasing a 2-year extended warranty does nothing for me.
You can go with something like a warrantech repairmaster 5 year extended warranty for $180(non-plasma TV under $2500), that will provide in-home service labor/parts for that time. It won't,however, cover new bulbs. That is a separate warranty.